Surface Modified Magnetic Nanoparticles as an Efficient Material for Wastewater Remediation: A Review

 Richa Tembekar¹, Kallol K. Ghosh^1,*, Angel Minj¹, Abhishek Katendra¹  

¹School of Studies in Chemistry, Pt. Ravishankar Shukla University, Raipur-492010, Chhattisgarh, India

 

ABSTRACT

Novel methods for management of environmental quality is directly proportional to the growth of the society. This paper reviews the advanced developments in the synthesis methods, surface modifications and applications of magnetic nanoparticles (MNPs) in environmental applications such as wastewater treatment and others. Surface modifications of magnetic nanoparticles with various inorganic, organic and biomolecules such as silicon dioxide, surfactants, metals etc. enhances the properties of the nanoparticles. The present review access the use of MNPs in removing the organic and inorganic contaminants present in the water bodies. Such methods are cost-friendly, eco-friendly, sustainable and easy to access as compared to other methods or techniques. Various organic and inorganic contaminants such as dyes, heavy toxic metals, pesticides, insecticides, pharmaceuticals etc. can be adsorbed or degraded by MNPs with high removal efficiency upto >95% and recycling upto 5 cycles with a minimum time span of 15 to 25 min. The novelty of the work on surface modified magnetic nanoparticles for wastewater remediation lies in several aspects such as enhanced adsorption affinities for particular contaminants, diverse functionalizations that enables targeting wide range of contaminants, synergic effects can enhance overall remediation and magnetic recovery provides access of easy separation and minimizing waste. The need for removal of such contaminants are necessary to reduce the harmful effects on plants, human as well as to aquatic beings.

Keywords: Magnetic nanoparticles, inorganic contaminants, organic contaminants, dyes, surface modifications, toxic effects, wastewater, removal mechanism.

1. INTRODUCTION

Nanoscale magnetic materials recently gained much more interest due to their potential functionalities (Abdullaera et al., 2012). Magnetic nanoparticles (MNPs) are nanoparticles (NPs) in the range of 1-100 nm with exclusive properties, such as high surface area to volume ratio and magnetic properties (Alagiri et al., 2011). These exclusive properties make MNPs particularly strong, versatile and reactive compared to their counterparts. MNPs including iron, cobalt and nickel NPs along with their respective oxides are one of the most promising materials that can be studied using external magnetic fields (Kroll et al., 1996). MNPs based materials such as pure magnetic metals (Fe, Co), alloys (nickel alloys) and ferrites (nickel ferrite, cobalt ferrite) with high saturation magnetization are usually preferred (Mahmoudi et al., 2009). Nowadays, researchers are focusing on synthesis of MNPs with various physical and chemical modifications. MNPs exhibit excellent physical and chemical properties like low toxicity, biocompatibility, large surface area, magnetism, high reactivity, high magnetic susceptibility etc. which makes them different from other nanoparticles (Ahmad et al., 2019, Zamay et al., 2020). Some of the well-known MNPs are hematite (α-Fe₂O₃), maghemite (γ- Fe₂O₃), magnetite (Fe₃O₄), wustite (FeO), and cobalt ferrite (CoFe₃O₄) (Choudhury et al., 2013, Sun et al., 2004). MNPs exhibit the most fascinating properties such as superparamagnetism, recyclability, reproducibility and the presence of non-equivalent ions in the crystal structure (Amiri et al., 2013). Among the various MNPs iron oxides became the most popular MNPs due to their high colloidal stability and biocompatibility compared to others. Magnetic properties of MNPs depend on the magnetic susceptibility, which can be defined by the ratio of induced magnetization (I) and the applied magnetic field (H) (Rodriguez et al., 2018). The magnetic susceptibilities of these materials depend on the temperature, external applied magnetic field and atomic structures (Zuluaga et al., 2007). MNPs show high performance in terms of chemical stability, superparamagnetic behaviour and sensitivity in comparison to other nanomaterials, which enables the different applications such as biosensing, catalysis, diagnosis and purification (Zhang et al., 2019; Kreissel et al., 2021; Berger et al., 2001).

The engineered MNPs with precision have been universally explored for the different novel applications in different fields (Gill et al., 2007). The wide range of applications of MNPs is due to their unique challenging and modular magnetic properties, MNPs have many interdisciplinary applications such as data storage, optical filters, tissue-specific targeting etc (Reziq et al., 2006). As a demand of time a new trend is developing for using MNPs for food analysis, wastewater treatment, catalysis etc. due to their high selectivity, sensitivity, adsorption and photocatalytic properties (Wierucka et al., 2014, Cao et al., 2012, You et al., 2021, Huang et al., 2015). In this respect MNPs are of noticeable importance and have been applied widely in the main field of research. The characteristic properties of MNPs such as high saturation magnetization, chemical stability and capacity to work at molecular and cellular levels enables them for huge varieties of applications in biological field (Gu et al., 2006, Cui et al., 2011; Santos 2014; Wang et al., 2015; Bai et al., 2014; Li et al., 2020; Cheng et al., 2009; Hasanzadeh et al., 2015; Wang et al., 2011). A wide variety of MNPs are applied in biological applications such as cell and protein separation, biosensor, tissue engineering and magnetic resonance imaging etc. (Marcus et al., 2018; Cole et al., 2011; Cole AJ, David et al., 2011; Xue et al., 2001; Kroll et al., 1996). The properties of MNPs varies with the different morphology, constituents, formulation parameters and design (Albornoz et al., 2006).

The MNPs can be synthesized by various methods such as sonochemical, co-precipitation, hydrothermal, electrodeposition, green method etc. (Low et al., 2018, Othman et al., 2018, Mdlovu et al., 2020, Yang et al., 2016). There are various advancements for controlling the physicochemical properties of MNPs. The regardless efforts are put to design, develop and improve stable and compatible MNPs (Zhang et al., 2021). MNPs stability is the crucial requirement as the pure metal forms are very sensitive in nature. Due to the instability and extremely reactive nature towards oxidizing agents, water and humid air (Jadhav et al., 2016). Thus, stabilization of MNPs is of prime importance and this can be achieved by surface functionalization (Wei et al., 2012; Shafaei et al., 2019). Surface functionalization must be done in a controlled manner with conjugated molecules that changes the structure, morphology and surface of the MNPs. Surface modification or fabrication of MNPs is done to enhance the stability, compatibility and uniformity of MNPs (As shown in Fig. 1.). This can be achieved with different surface stabilizing groups such as organic (carbohydrates, carbon coating etc.), inorganic (metal oxides, graphene etc.), biomolecules (amino acids, vitamins etc.) and different surface-active groups (Prasad et al., 2016; Yuvakkumar et al., 2014; Rajiv et al., 2017; Behestkhoo et al., 2018). The surface modification or fabrication of MNPs improves both colloidal and physical stability of the particles, increasing water dispersibility and provide conjugation sites (Jin et al., 2014). The MNPs based composites and surface modification enhances the properties of MNPs. The structures of composite, nanoparticles made of MNPs and organic molecules such as ligands as well as nature of interaction and associated molecular structure enhances the physicochemical properties of MNPs (Arvand et al., 2017). The synthesis of MNPs composites can be achieved with the help of monomers or polymers gives the structural stability to the MNPs by generating polymeric shelf. Likewise, protection of MNPs from oxidizing and colloidal stability of MNPs can be achieved by surface coating by using polymeric stabilizers or surfactants such as dextran, polyvinyl alcohol (PVA) etc. Similarly, lipids like liposomes etc. can be used for surface functionalization which can be considered as promising candidates for tumor hyperthermia, magnetic cell separation and various biological applications (Lin et al., 2006).                              

 

Fig. 1 The scheme of MNPs design workflow

2. SYNTHESIS OF MAGNETIC NANOPARTICLES

There are various physical, chemical and biological known methods for the synthesis of MNPs and its composites. Physical method involves ball milling, vapour deposition pattern, gas phase deposition, electron beam lithography, electrical explosion of wires (Carvaeho  et al., 2013; Granata et al., 2013; Hyeon 2003). Whereas chemical method involves co-precipitation, sonochemical, hydrothermal, microemulsion, pyrolysis, sol-gel method etc. (Mohammed et al., 2017, Perez et al., 1997, Xu et al., 2007, Andrade et al., 2009, Hong et al., 2007). There are various biological methods also, for the synthesis of MNPs in which plants and microorganisms plays a crucial role (Hasanpour et al., 2007).

2.1. PHYSICAL METHODS

2.1.1. Ball Milling

One of the known physical methods is ball milling method in which large particles are crushed into ultrafine small particles without the involvement of chemical reactions (Zhang et al., 2020). For the synthesis of different MNPs, different ball milling powders are used. For iron oxide nanoparticles, wet iron powder is added, for cobalt oxide NPs, cobalt powder is added to a container along with several heavy balls and mechanical energy is applied on it with the help of high-speed rotating ball (Kurlyandskaya et al., 2014). This method is considered as one of the best methods for large scale production of MNPs with high purity.

2.1.2. Electrical Explosion of Wires

The electrical explosion of wires is the rarest method for the synthesis of MNPs. In this method intense current is provided to make the metal wire gets evaporated (Bao et al., 2016). The NPs produced by this method are very pure and spherical in shape. It is considered to be as green method as this method does not produces any toxic by-products.

2.1.3. Electron Beam Lithography

Electron beam lithography use electron beams with 10-100 keV energy per electron. In this method electron beam is used to convert the larger target atom into nano-sized materials (Wang et al., 2019). This method is one of the low costs, easily accessible and less time-consuming method to produce stable MNPs like iron oxides (Fe₃O₄, Fe₂O₃), cobalt oxide (Co₃O₄) NPs (Swihart, 2003).

2.1.4. Vapour Deposition Pattern

 MNPs can be synthesized by the formation of a continuous film and filling holes in the available templates. The deposition of particles occurs through vapour deposition techniques like evaporation, laser ablation, electrodeposition and sputtering etc. (Franzel et al., 2012; Hasanzadeh et al., 2016; Wagener et al., 1999). This method is advantageous as it can be employed for large scale production with high quality of MNPs. Chen and co-workers (Chen et al., 2002) synthesized the platinum cobalt MNPs by chemical vapour deposition method. Platinum and cobalt NPs were homogenously distributed on the carbon support, followed by thermal treatment.

 

2.2. CHEMICAL METHODS

2.2.1. Co-Precipitation Method

Co-precipitation is easy and most convenient method for the synthesis of MNPs. In this method a base like NaOH or NH₄OH is added to a solution containing mixture of metal precursors with different oxidation states for the synthesis of MNPs (Katepetch et al., 2011). Wulandari et al. (Wulandari et al., 2017) used ex situ co-precipitation method to produce chitosan coated MNPs. Ferric chloride and ferrous sulphate were used as metal precursors and ammonium hydroxide as base. Surface modification by chitosan was employed to prevent oxidation of magnetite to maghemite.

2.2.2. Hydrothermal Method

The hydrothermal method is a known method for the synthesis of MNPs. In this method the solution is enclosed in a sealed reactor under high pressure, high temperature and other reaction conditions (Ozel et al., 2015). Moreover, this method is advantageous over others as it produces MNPs with desired shape, size and crystallinity. Wu et al. (Wu et al., 2014) synthesized magnetic Fe₃O₄@C NPs by a simple hydrothermal method. Fe₃O₄ was prepared by ferrous chloride and ferric chloride and its functionalization was done by glucose as a source of carbon. The synthesized material was further studied for the adsorption of dyes.

2.2.3. Sol Gel Method

The sol- gel method includes mixing of compounds containing chemically active ingredients in a liquid phase environment (Moradnia et al., 2021). A reaction such as hydrolysis or polycondensation forms a stable transparent sol system in a solution. Sols get converted into a transparent gel and further dried or heated to prepare the NPs. Shankar et al. (Shankar et al., 2023) synthesized MNPs by sol gel by using ferric nitrate and ethylene glycol as precursors with varying the temperature. The method is environment friendly, inexpensive and produced size controlled MNPs.

2.2.4. Microemulsion Method

In microemulsion method, precipitation of MNPs from microemulsion solution takes place. In this process agglomeration, growth and nucleation occurs. In order to form the microemulsion, it is important to adjust the ratio of surfactant, oil phase and solvent phase (Salabat et al., 2018). Tonghan et al. (Tonghan et al., 2019) used a multiphase segmented flow reaction system for the synthesis of MNPs by microemulsion method.

2.2.5. Sonochemical Method

Sonochemical method is one of the best methods for the synthesis of MNPs. It is advantageous over other methods as it has very low requirements and synthesis takes place under ultrasonic sound waves (Abba et al., 2012) Garcia et al. (Garcia et al., 2020) used ultrasonic chemical reactions to rapidly synthesize MNPs with uniform particle size. The method is rapid and less time consuming. The group used FeSO₄ as precursor salt and NaOH as reducing agent in aqueous medium. The concentration of NaOH was varied throughout the synthesis to optimize the size of formed MNPs.

2.2.6. Electrodeposition Method

The electrodeposition method is the process by which a precursor is deposited onto a substrate to form a nanostructure. The reaction is usually carried out with dissolved metal ions like Fe²⁺, Fe³⁺, Co²⁺, Ni²⁺ ions as a precursor (Tartaj et al., 2001). The preparation of MNPs has a broad application prospects. Wang et al. (Wang et al., 2012) synthesized a Ni/Fe₃O₄ composite and coated it with carbon fibers by electrodeposition method. The developed composites i.e. carbon fibers coated with Ni/Fe₃O₄ NPs composites coating exhibits higher thermal stability and saturation magnetization.

TOP DOWN AND BOTTOM UP APPROACHES OF MAGNETIC NANOPARTICLES SYNTHESIS

(A) TOP DOWN

Top down method generally refers to the approach where larger materials are converted into nanoscale materials via several synthesis methods (as shown in Fig.2)

Ø  Ball milling method

Ø  Lithography method

Ø  Etching method

(B) BOTTOM UP

In contrast, bottom up approach is a process in which nanosized materials are formed by many tiny atoms or molecules via several synthesis methods:

Ø  Sol-gel method

Ø  Self assembly method

Ø  Chemical vapour deposition method

 

Fig.2 Schematic representation of Top down and Bottom up synthesis methods

 

2.3 BIOLOGICAL METHODS

To overcome the cost, time and environmental hazards related issues, it’s an urge to ecofriendly method. The biological method is gaining much more attention as chemical requirements are very less in this method and hence does not produce harmful effects (Table 1).  Microbes and plants both offers pathways for the synthesis of MNPs (Joshi et al., 2018). Parts of the plants like barks, tissues, roots are used for the synthesis of different MNPs. This method is much more beneficial over other methods as they give better reproducibility, scalability, higher yield and controlled size of the NPs. Majidi et al. (Majidi et al., 2016) synthesized the MNPs by using various parts of plants including leaves, barks, tissues etc. The extract of plants contains reducing and stabilizing agents such as polyphenols, catechin, flavonoids, ascorbic acid, citric acid, dehydrogenases and reductases for the synthesis of MNPs.

     Table 1. Microorganisms doped for the synthesis of other metal nanoparticles.

 

2.4. COMPARISION BETWEEN PHYSICAL, CHEMICAL AND BIOLOGICAL SYNTHESIS METHODS

A comparative study was done among all the three methods - physical, chemical and biological/green methods for the synthesis of MNPs (Fig. 3.). According to the study it was found that the chemical methods for the synthesis of NPs are more suitable over physical methods, as physical method requires more manpower, high energy consumptions (Kim et al., 2013). Chemical methods also have some of the adverse effects as they are toxic, costly and sometimes causes threats to the environment as well as hazardous to human beings as well. Nowadays green or biological synthesis provides an edge over physical and chemical methods. They are more advantageous as they are nontoxic, easily available and raw materials (Table 2) (microorganism, plants) are cost friendly and eco-friendly as well. Ali et al. (Ali et al., 2017) reported biological methods are advantageous over other methods as they are obtained from natural sources like plants and microorganisms.

Fig. 3  Different methods for synthesis of MNPs  Table 2. Advantages and disadvantages of synthesis methods of nanoparticles.

SYNTHESIS METHODS	ADVANTAGES	DISADVANTAGES
PHYSICAL METHOD	ü  Less use of toxic chemicals ü  Uniform size and shape ü  Large production	ü  High energy consumption ü  Large amount of waste ü  Expensive
CHEMICAL METHOD	ü  Easy synthesis ü  Fast reaction ü  Controlled size	ü  Hazardous ü  Low purity ü  Unstable
BIOLOGICAL METHOD	ü  Biocompatible ü  Simple and facile ü  Non-toxic	ü  Poor control over size ü  Time consuming ü  Low yield

 

3. SURFACE MODIFICATIONS

The surface modification of different materials of MNPs can be done by surface fabrication or functionalization, which enhances the properties of MNPs as well as its area of applications. Different, surface coating protects the synthesized MNPs from aggregation, its further oxidation and increases its stability. Surface modifications of MNPs can be done by materials such as surfactants, silicon dioxides, polymers, metals, metal oxides/sulphides, carbon coating, biomolecules etc. (Yang et al., 2019; Tiefenauer et al., 1993; Wang et al., 2008). Some of the surface modified MNPs such as nano chitosan coated MNPs, starch coated MNPs.

3.1 Silicon Dioxide

Due to the widespread application of MNPs in the various fields, coating silica on its surface has become a research hotspot (Vojoudi et al., 2017). Non-toxic silica is a very ideal surface functional coating for MNPs, as it forms an inert external shielding layer to protect the nanoparticles. Jouyandeh et al. (Jouyandeh et al., 2018) first synthesized magnetite nanoparticles, then modified them with silicon dioxide and chitosan to finally prepare Fe₃O₄/SiO₂/chitosan nanocomposites. Therefore, various functional group modifications can be performed on the surface of MNPs for applications such as catalysis, adsorption and magnetic separation.

3.2. Surfactants

To prevent the agglomeration of MNPs, surface modifications of MNPs can be done with the help of surfactants like cetyltrimethyl ammonium bromide (CTAB), sodium dodecyl sulphate (SDS), cetyl pyridinium chloride (CPC) (Duan et al., 2020). Surfactant-functionalized MNPs can be easily divided into oil-soluble and water-soluble (Guo et al., 2020).  Heidari et al. (Heidari et al., 2016) reported a method for synthesized MNPs and its surface modification with CTAB. Maleki and co-workers (Maleki et al., 2023) synthesized SDS micelles coated Fe₃O₄/SiO₂ MNPs and studied its adsorption on crystal violet.

3.3. Metals

Another simple way to prevent MNPs from oxidation is to modify their surface with metals like gold, manganese, silver (Bradley et al., 2013). The protection of the metal layer expands the application ranges in interdisciplinary areas and its application in the field of biomedicine, environment and catalysts gradually increases. The effect of different metals on their surface brings a diversification in their properties. Wang et al. (Wang et al., 2016) successfully synthesized Au coated MNPs with different functions and hence is used for bacterial detection.

3.4. Carbon Coating

The surface modification of MNPs can also be achieved by carbon coating with the help of carbon-based materials like carbon fibers, graphene etc. Among them carbon fiber has excellent electrical properties, high strength, and low density. In particular, iron oxide NPs composite coatings have gained more and more scientific and industrial interest due to their electrical conductivity and high permeability. Qiao and co-workers (Qiao et al., 2020) used a simple and controllable method to synthesize Fe₃O₄@carbon composite microspheres. The deposition of Fe₃O₄ nanoparticle composite coating on the surface of carbon fiber fields increases its application in the field of degradation, microwave absorption, batteries, drug loading etc.

 

3.5. Metallic Oxide/Sulfides

Surface modification of MNPs can also be done by metal oxides like SnO₂,MnO₂,Al₂O₃, TiO₂, MgO etc. (Zhang et al., 2016, Banerjee et al., 2018, Wang et al., 2018) or metal sulfides like ZnS,Co₃S₄, Ni₃S₂ etc. (Li et al., 2017, Du et al., 2017, Bujnakova et al., 2017) can also act as protective shells for MNPs. Rasouli et al. (Rasouli et al., 2023) developed a ternary nanocomposite made of titaniumdioxide (TiO₂) and ferric oxide (Fe₂O₃), which can act as a photocatalysts. MNPs can also be protected by metal oxide surfaces or metal sulfides which have widespread applications in various fields. Sun et al. (Sun et al., 2018) synthesized Fe₃O₄/ZnO nanocomposites by coating zinc oxide magnetic core (Fe₃O₄) with ammonium hydroxide as the basic medium.

3.6. Biomolecules

Surface modification of MNPs with biomolecules enhances its properties as well its applications (Maltas et al., 2011) (Fig. 4.). Biomolecules such as proteins, polypeptides, antibodies, amino acids, vitamins can bind with MNPs through a certain functional group (Soshnikova et al., 2013).  Biocompatibility of the MNPs can be widely applied in biological and environmental applications. Chen and co-workers (Chen et al., 2019) synthesized L-cysteine modified magnetic mesoporous silica microsphere for endogenous recognition of glycopeptides.

 Fig. 4 Interactions of functionalized MNPs with targeting agents

4. PROPERTIES OF MAGNETIC NANOPARTICLES

MNPs exhibits various physical and chemical properties like catalytic property, magnetic property, adsorption property, optical property and others which are discussed below.

As (Fig. 5). (Mohammed et al., 2017) depicts the schematic representation of adsorption and reduction of MNPs. M⁺ stands for the metal ion and here iron in the metal which is represented in the form of Fe₃O₄ (magnetite) and ϒ-Fe₂O₃ (maghemite). The overall cycle explains two processes, firstly the transitions of M⁺ to M⁰ during the process of reduction where iron gets reduced from +1 to 0 oxidation state and secondly M⁺ to M⁺ during adsorption where no change in oxidation state takes place. In Fe⁰ condition a layer of iron oxide gets formed.

Fig. 5 Schematic representation of adsorption and reduction potential of MNPs  4.1. Plasmonic Properties:

 Optical properties of NPs arise due to the localized surface plasmon resonance (LSPR) that is associated with the oscillations of electrons, in the presence of electromagnetic radiation (Meenach et al., 2010).  It is based on the size, shape and surface of the MNPs which can be applied as optical detectors, laser sensors, solar cell, photocatalysts etc. Villegas et al. studied the photocatalysis of nitrobenzene. At 15 ppm concentration, its absorbance peak was obtained at 254 nm.

4.2. Magnetic Properties: 

Metals like iron (Fe), cobalt (Co), nickel (Ni) usually show magnetic properties. Evaluating the magnetic properties of nanopaticles is very crucial for determining their efficiency, recyclability, reusability, separation and recovery. Permanent magnetization is not seen when the paramagnetic materials are withdrawn from the magnetic fields in contrast ferromagnetic materials shows persistent magnetic behaviour when removed from magnetic fields. Their properties depend on the surface area, volume and capping agents (Chorny et al., 2007). However, some of the NPs also shows magnetic properties when they are capped with appropriate molecules, the charge localized at the particle surface gives rise to ferromagnetic like behavior. Such property leads MNPs to act as sensing devices. Khan et al. (Khan et al., 2021) reported that the magnetic properties also helps in separating the catalyst by centrifugation, filtering, or extraction processes for the treatment of wastewater. MNPs acts as a catalyst that efficiently remove various organic and inorganic contaminants from wastewater (Mcbain et al., 2007).

4.3. Electrical Properties:

Electrical properties of MNPs deal with the electrical conductivity of the NPs, nanomaterials or nanocomposites. Metals generally possess high electrical stability and excellent electrical conductivity. Due to their high conducting capacities, they can be utilized in developing electronic sensors conducting electronic devices etc. (Liu et al., 2011).

 4.4. Catalytic Properties:

MNPs play a significant role in catalysis due to their increased surface to volume ratios (Luo et al., 2008). Hence this property of MNPs helps in minimizing the harmful effects on both environment and mankind. The MNPs was synthesized by green synthesis method and the degradation of bromophenol blue was influenced by the addition of H₂O₂ under UV light.

 5. APPLICATIONS OF MAGNETIC NANOPARTICLES                                         

 MNPs have a wide range of notable applications in the environmental, industrial, agricultural, biomedical, fabrics, minerals, magnetic fluids, chemical industries and other fields such as catalysis, wastewater treatment etc. (Cui et al., 2016, Pepping 1999, Pandya et al., 2016, Kheilkordi et al., 2022, Mourdikoudis et al., 2018, Jiaqi et al., 2019) These applications highlights  the importance and versatile behavior of MNPs in the world of technology and innovations.

5.1. Application of MNPs in Wastewater Treatment

MNPs are gradually gaining attention as promising materials for environmental applications. The unique physiochemical properties of MNPs due to large surface area, ease of synthesis and inherent superparamagnetic properties which leads to their widespread applications (Weteskog et al., 2017). Like silica based nanoadsorbent removal of pharmaceutical substances etc. Wastewater has adversely affected human as well as plants and animals’ life. The treatment of wastewater is one of the serious issues that cannot be avoided (Sivakami et al., 2020). There are some pre-established methods like water treatment plants, but they are very expensive and requires manpower. MNPs have very good adsorption capacity, as well as their property enhances due to surface functionalization (Rana et al., Bui et al., 2018). As MNPs possesses large surface area for adsorption, they can be used for the removal of dyes during wastewater treatment. MNPs are widely used in the detection and removal of toxic metals like Cr, Cd etc. (Cui et al., 2014, Harkness et al., 2010).

Fig 6 Stepwise process of wastewater treatment by MNPs.

5.1.1 ORGANIC CONTAMINANTS

The cyclic process of wastewater treatment is discussed briefly in (Fig.6). (Huang et al., 2013) Surface functionalized magnetic nanoparticles are dispersed into the wastewater containing several types of contaminants. Due to its excellent superparamagnetic properties, the surface functionalized MNPs adsorbs the contaminants on the surface of MNPs and hence gets separated. On applying the magnetic field the MNPs gets detached from the contaminants and are ready to be used for another cycles for wastewater treatment.

MNPs is efficiently used for the removal of organic pollutants present in the water bodies. Organic wastes which enters the water bodies due to waste disposals from households and hospitals, agricultural activities, combustion processes, industrial activities (textile, cosmetics, pharmaceuticals, paint, leather and food industries) that leads to contamination of water (Mollarasouli et al., 2021, Li et al., 2018, Jung et al., 2011, Chen et al., 2017). Pollutants such as dyes, oil, pesticides, fertilizers and other phenolic compounds are common which leads to environmental pollution especially water contamination (Fig. 7.) . Organic dyes are highly toxic, carcinogenic in nature as well as creates many harmful effects on human beings and threat to aquatic lives (Table 3.). Huang et al. (Huang et al., 2015) synthesized iron nanoparticles (Fe-NPs) for the degradation of malachite green (MG) and hence studied the conditions impacting on its reactivity. Finally degradation study showed that 90.56% of MG was removed using Fe-NPs. Aydin et al. (Aydin et al., 2021) synthesized simple and cost effective method for removal of psychiatric drugs from wastewater. The group studies the adsorption capacity of magnetite red mud nanoparticles (RM-NPs) for effective removal of carbamazepine from wastewater treatment plant effluents. Nawara et al. (Nawara et al., 2012) studied the adsorption of doxorubicin drug on the citrate stabilized magnetic nanoparticles. They synthesized the citric-acid-stabilized magnetic nanoparticles with very good magnetization behaviour. They reported a novel method utilizing a ternary system for the determination of interactions between drug and citric-acid-stabilized nanoparticles. Weng and co-workers synthesized iron-based nanoparticles from green tea extract. As green tea contains polyphenols and catechins which acts as reducing agent in the synthesis. The synthesized GT-MNPs was later studied for the degradation of malachite green (MG). The pH, initial concentration of MG, the dosage of GT-MNPs and the reaction temperature was also investigated. It emerged that 96% of MG was removed with a 50 mg/L at 298 K (Weng et al., 2013). Kinetics studies showed that the removal of MG fitted well to the pseudo first-order mode. Islam and his group (S. Islam et al., 2020) studied the antimicrobial activity of citric acid functionalized iron oxide nanoparticles and their superparamagnetic effects on it. They synthesized the iron oxide nanoparticles by sol gel method. These magnetic nanoparticles are functionalized with different concentrations of citric acid such as 0.1 M, 0.2 M, 0.3 M, 0.4 M and 0.5 M. 0.3 M concentration showed super paramagnetic behaviour. Iron oxide functionalized with citric acid concentration of 0.3 M resulted in high saturation magnetization of 85emu/g with hydrodynamic diameter size almost equal to 25 nm. Thus it was confirmed that 0.3 M concentration of citric acid functionalized nanoparticles  appeared to be beneficial for antimicrobial activity. Atta et al. (Atta et al., 2020) synthesized poly (ionic liquid) functionalized silver and magnetite nanoparticles. Magnetite nanoparticles were prepared with protic poly(ionic liquid) based on a quarternized diethylethanolamine cation combined with 2-acrylamido-2-methylpropane sulphonate-co-vinylpyrrolidone (QAMPSA/VP) as a capping and reducing agent. The kinetics of the catalytic reduction of MB with QAMPSA/VP-Ag NPs was investigated using UV–vis spectroscopy. The intensity of the MB band at 662 nm disappeared completely after 12 minutes and it was also noticed that the colour of MB  changed from blue to colourless. (Table 4 and 5).

Fig 7. Classification of Dyes.

Fig. 7 Classification of organic dyes

Table 3. Toxic dyes and their adverse effects in human body.

DYES	CLASS	TOXIC EFFECTS IN HUMAN BODY
Alizarin Red S	Anthraquinone	Mutagenic, carcinogenic, causes oxidative damage
Azocarmine B	Quinone-imine	Allergic reactions, vomiting, carcinogenic, poisonous
Bromophenol Blue	Triaryl methane	Respiratory tract infection, skin irritation, carcinogenic
Congo Red	Diazo	Genotoxic, teratogenic, mutagenic, carcinogenic
Crystal violet	Triaryl methane	Chromosomal damage, respiratory and renal failure, digestive tract disorders
Eosin B	Fluorone	Nausea, chest pain, skin irritation, dizziness, rapid heart rate
Eriochrome Black T	Azo	Cytotoxicity, skin irritation, respiratory issues
Erythrosine	Azo	Allergies, neurotoxicity, DNA damage behavior, carcinogenic
Fluorescein	Fluorone	Hypotension, skin inflammation, renal failure, pulmonary edema, nerve palsy
Indigo	Indigoid	Allergic reactions, vomiting, intestinal problems
Malachite Green	Triaryl methane	Liver damage, spleen damage, tumors in lungs and ovary
Methylene Blue	Thiazin	Respiratory disorders, overactive reflexes Central nervous system failure, dermatological issues
Methyl Orange	Azo	Vomiting, gastrointestinal irritation, respiratory tract infection
Phenolphthalein	Phthalein	Abdominal pain, allergic skin rash, dizziness, digestive tract or respiratory tract irritation
Rhodamine B	Rhodamine	Liver dysfunction, pre-mature birth, kidney  damage, cardiovascular diseases
Rhodamine 6G	Rhodamine	Skin irritation, blindness, respiratory tract infection, carcinogenic
Safranin	Azo	Liver infection, kidney damage, respiratory tract irritation
Thionin	Thiazin	Itching, skin rashes, fast heart rate
Vat Green 1	Anthraquinone	Skin irritation, eyes irritation, carcinogenic, allergic reactions

 

 

Table 4. Surface modified MNPs and their applications in organic dye removal. S.No.	Name of MNPs	Contaminants removed	Removal mechanism	Removal efficiency	Contact Time	Amount	Reusability/ Recyclability	References
1.	Starch coated MNPs	Rhodamine B dye	Photocatalytic degradation	97%	30 min	10 mg/ 3 ml	Upto three cycles for 92% removal	Sharma et al., 2019
2.	Copper doped ZrO2 MNPs	Methyl orange dye	Photocatalytic degradation	98%	100 min	-	Up to four cycles for 90% removal	Reddy et al., 2020
3.	Epoxy-Triazinetrione- Functionalized MNPs	Malachite green	Adsorption	95%	15 min	-	Up to six cycles for 61% removal	Nejad et al., 2020
4.	Ionic liquid coated MNPs	Rhodamine B	Adsorption	91%	14 min	-	Upto three cycles for 55% removal	Chen et al., 2016
5.	Combination of Fe2O3 and Fe3O4	Bromophenol blue dye	Photocatalytic degradation	98%	60 min	5 mg/L	Up to three cycles for 95%  removal	Fatimah et al., 2020
6.	Fe3O4/CeO2	Acid black 210	Adsorption	90%	120 min	-	Upto two cycles for 80% removal	Gao et al., 2018
7.	Humic acid functionalized Fe3O4	Malachite green dye	Adsorption	97%	35 min	25 mg/L	Up to five cycles for 85%  removal	Gautam et al., 2020
8.	Polyethyleneimine and magnetic nanoparticles	Black 5 dye	Adsorption	100%	180 min	20 mg/L	Upto 5cycles for 48% removal	Nordin et al., 2021

 

Table 5. Surface functionalized MNPs and their applications in removal of organic conmatinants.

S.No.	MNPs	Synthesis Method	Contaminants removed	Removal Mechanism	Removal Time	Removal Efficiency	References
1.	Magnetic silica based nanoadsorbents	Polyol  method	Pharmaceutical substances	Adsorption	200 min	80%	Peralta et al., 2021
2.	Silica coated ferro-ferric oxide (Fe3O4@SiO2)	Solvothermal method	Emulsified oils	Transformation	05 min	98%	Lu et al., 2020
3.	FeNi3@ SiO2@TiO2	Co-precipitation and Sol gel method	Humic acid	Photocatalytic degradation	30 min	100%	Khodadadi et al., 2020
4.	Chitosan coated magnetic nanoparticles	Co-precipitation method	Biorefinery wastewater containing phenol	Adsorption	90 min	46.2%	Rathan et al., 2020
5.	Magnetic Janus nanoparticles	Sonochemical method	Cooking oil and crude oil	Phase separation	15 min	96%	He et al., 2020
6.	Magnetic activated carbon-Fe3O4	Co-precipitation method	Pharmaceutical substances	Adsorption	06 min	99.97%	Cruz et al., 2020
7.	Nanoporous Co2O3/Cu2O3:Al2O3:SiO2	Sol gel  method	E. faecalis	Disinfection	05 min	100%	Hammad et al., 2020
8.	Novel MNP-alum conjugate	Co-precipitation method	Natural organic matter	Adsorption cum enhanced coagulation flocculation	30 min	98.7%	Kumari et al., 2020

 

5.1.2. INORGANIC CONTAMINANTS

MNPs can also be utilized for the removal of inorganic pollutants. Inorganic wastes includes heavy metals as toxic substances such as mercury, lead, copper, arsenic, chromium etc. (Shukla et al., 2021; Chlebowski, 1979) (Table 6.). These pollutants can also be removed from wastewater using MNPs. Low cost, eco-friendly MNPs are reliable as an adsorbent for removal of toxic metal ions from water bodies. MNPs and their composites are showing their excellency in removal mechanism as well as can be recycled after each and every use (Table 7.). Divalent ions like copper, nickel and cobalt were effectively removed using polymer grafted Fe₂O₃  nanocomposite (He et al., 2018). Takafufgi et al. have studied the removal of arsenic by iron oxide nanoparticles (Fe₂O₃ and Fe₃O₄) [163].

 

Table 6. List of toxic metals and their hazardous effects on human body.

TOXIC HEAVY METALS	ILL EFFECTS IN HUMAN BODY	MCL(mg/l)
Pb	Circulatory disorders, renal damage, reproductive problems, gastrointestinal problems	0.006
Cr	Skin irritation, Nausea, Diarrhea, Headache, carcinogenic	0.05
As	Skin pigmentation, vascular diseases, ulceration, visceral cancer	0.05
Zn	Nausea, lethargy, intestinal irritation, increased thirst, depression	0.08
Cd	Renal dysfunctions and damage, osteomalacia, bone degeneration, carcinogenic	0.01
Hg	Nervous system damage, cardiovascular damage, gastrointestinal problems, death	3
Cu	Cirrhosis, haemolysis, insomnia, liver damage, Wilson disease	0.25
Ni	Asthma, lung fibrosis, cardiac arrest, contact dermatis	0.02

 

5.2 MECHANISMS OF REMOVAL OF CONTAMINANTS USING MNPs

Environment is adversely affected due to increasing population and rapid industrialization. MNPs plays a crucial role in the treatment of wastewater by removal/degradation mechanisms. There are four basic mechanisms catalysis, adsorption, filtration and transformation (Li et al., 2019). Catalysis is very efficient and cheap methd in which removal of contaminants requires light active catatlyst made up of MNPs. The degradation of variety of wastewater contaminants can be degraded using this mechanism (Fig. 8). Filtration or nanofiltration is a membrane separating technique in which removal of  contaminants takes places by osmosis, reverse osmosis, permeation (Ali et al., 2019). It is a selective process for removal of the inorganic and organic contaminants like suspended solids, pharmaceutical wastes, bacteria etc. The mechanism follows three steps : (i) Transport of the contaminants to the filter medium (ii) Separation at the filter medium (iii) Collection of contaminants and the MNPs . Transformation is a process in which the removal is done by oxidation/reduction. The redox reaction reduces the metal toxicity and is one of the excellent method for removal of both inorganic and organic contaminants (Kumar et al., 2018). Adsorption  is a surface phenomenon in which  contaminants gets adsorbed on the surface of the MNPs through physisorption  (the enthalpy is low 20-40 kJ/mol) and chemisorption (entalpy is higher 40-400 kJ/mol). The adsorption process occurs in three steps :    (i) movement of contaminants on the surface of MNPs (ii) binding on the surface of MNPs (iii) movement within the adsorbent. Further adsorption could be studied by various adsorption isotherms : (a) Langmuir adsorption isotherm (b) Freundlich adsorption isotherm (c) BET isotherm (d) Temkin. The nanosized pores of the surface of NPs helps in adsorption of the contaminants (Das et al., 2020). Due to its excellent magnetic properties the contaminants gets separated by the MNPs and can be reused.

Fig.8 Mechanism of photocatalytic degradation by MNPs (a) Inorganic pollutants (b) Dyes

(a)   Langmuir adsorption isotherm

Where,    = is the adsorbents maximum adsorption capacity (mg/ g)

               = theoretical maximum adsorption capacity (mg/ g)

               = Langmuir adsorption constant (L/ mg)

               = concentration of contaminants

 

(b)  Freundlich adsorption isotherm

                                                     

Where,  = is the adsorbents maximum adsorption capacity (mg/ g)

               = intensity of heterogeneity factor

              = freundlich adsorption constant (L/ mg)

              = concentration of contaminants

(c)   Temkin adsorption isotherm

                                                    

Where,  = is the adsorbents maximum adsorption capacity (mg/ g)

              = heat of adsorption (KJ/ mol)          

              = temkin isotherm equilibrium binding constant (L/ g)

             = concentration of contaminants

 

(d)  BET adsorption isotherm

                                                                             

Where, W = weight of gas adsorbed

               = relative pressure

               = weight of adsorbate as monolayer

                = BET constant

            

Table 7. MNPs and its application in removal of inorganic contaminants.   Adsorbents	Size (nm)	Targeted Toxic Metals	Adsorption Capacity(mg/g)	Removal Efficiency (%)	Reference
Magnetite	8-35	Cd(II)        Ni(II) Cr(VI) Cu(II)	7.45-35.46	Cd- 99.8% Ni-88.5% Cr- 97.6% Cu-99.8%	Predescu et al., 2015
Maghemite nanotubes	250	Cu(II) Pb(II) Zn(II)	Cu-111.1 Pb-71.42 Zn-84.95	95% in synthetic   water	Roy et al., 2012
Nanoscale zero valent iron	56	As(III) As(V)	As(III)- 102 As(V)-118	90% in synthetic   water	Yin et al., 2022
Magnetite hematite nanoparticles	4-52	Pb(II) Cr(III) Cd(II)	Pb-617.3         Cr-277 Cd-223.7	>96% in synthetic water	Ahmed et al., 2013
Magnetic graphene	2-30	Cd(II) Pb(II)	Cd-234 Pb-14	93% in synthetic water	Bao et al., 2020

 

5.3. Environmental Sensing

Functionalized or surface modified MNPs can be used as sensors for the detection or sensing of target analytes (Table 8 and 9.). As they binds with the target contaminants such as heavy metals and other analytes like organic dyes (Ma et al., 2018) (fig.8). It has efficiency towards the detection of organophosphorus pesticides (OP) such as malathion, parathion, methyl parathion, diazinon etc. (Sahu et al., 2024). As OP causes contamination of water and agricultural products. It can also detect the antibiotics such as tetracyclines, penicillin etc. present in the environmental samples Fig.9. shows a pie chart of contribution of work related to wastewater treatment by MNPs.

 

Table 8. Surface functionalized MNPs and their applications as sensors. S. No.	Name of Nanoparticles/ Composition	Metal	Applications Sensor	References
1.	Graphene oxide aerogel decorated with Pd-Fe nanoparticles	Iron	8 biomolecules ascorbic acid (AA), dopamine (DA), uric acid (UA), 8-hydroxyguanine (8HG), guanine (G), adenine (A), thymine (T), and cytosine (C)	Ferrag et al., 2023
2.	Copper iron mixed metal oxides nanoparticles/ reduced graphene oxide composite	Iron	Ciprofloxacin	Chuiprasert et al., 2024
3.	Magnetic iron based nanoparticles	Iron	Ascorbic acid	Uzunoğlu et al., 2022
4.	Zerovalent iron nanoparticles	Iron	Cadmium (II) Lead (II)	Djebbi et al., 2022
5.	Cobalt doped ZIF-8 nanoparticles	Cobalt	Copper	Menon et al., 2024
6.	Lanthanum cobalt oxide nanoparticles wrapped graphitic carbon nitride nanocomposites	Cobalt	perphenazine	Koventhan et al., 2023
7.	Cobalt doped cerium oxide nanoparticles embeded graphitic carbon nitride	Cobalt	Fenitrothion	Đurđić et al., 2024
8.	Cobalt oxide nanoparticles	Cobalt	LPG gas sensor	Poonguzhali et al., 2023
9.	Graphene/ Nickel oxide based nanocomposite	Nickel	Ammonia	Ahmad et al., 2018
10.	Au Quantum dot/ nickel tetrainophthalocyanaine-graphene oxide	Nickel	Epinephrine detection	Huang et al., 2020
11.	Carbon nanotubes decorated molybdenum disulfide decorated with nickel nanoparticles	Nickel	Glucose	Fall et al., 2023
12.	Nanostructured nickel oxide electrodes	Nickel	Glucose	Singer et al., 2020

 

Table 9. Different types of MNPs and its applications.

S.No	MNPs	Application	References
1.	Iron (Fe)	·        Magnetic imaging ·        Environmental remediation	Macdonald et al., 2008
2.	Cobalt (Co)	·        Catalysis ·        Energy storage	Maiti, 2020
3.	Nickel (Ni)	·        Magnetic removal ·        Catalyst	Akbari et al., 2020

 

Fig.9 Percentage contribution of publications on application of MNPs in wastewater treatment over the period of 10 years (2014 - 2024)   (Mar 2014 - Mar 2024).

  6. FUTURE PERSPECTIVE

It is evident that many technologies aimed at enhancing the standard of our living environment can greatly benefit from the intrinsic qualities of MNPs. The applications of MNPs are immensely increasing worldwide in different fields like biomedicines, environment, chemistry and material science. Each method has its own particular advantages and disadvantages. Green approach for synthesis of nanoparticle is sustainable, eco-friendly, inexpensive and generally free of chemical contaminants. Moreover metal/metaloxides and nanocomposites can be used as photocatalysts for photocatalytic degradation of organic dyes, removal of toxic metals, drug etc. This review reflects the fact that most research utilizing MNPs for environmental applications has focused on wastewater treatment, whether it be through groundwater and soil remediation or magnetic separation and/or sensing of contaminants present in various aqueous systems. Both the utilization of functionalized MNPs for removal by adsorption and separation and nZVI for pollutant degradation are now well-known domains in which the fundamentals of operation have been defined and repeatedly demonstrated for a variety of systems. Hence it is supposed that MNPs can be used in future for environmental remediation and will be helpful in reducing health risk factors. Due to its various physiochemical properties, it will be applicable to interdisciplinary areas.

7. CONCLUSION

The recent review has aimed to elaborate the role of MNPs in reducing environmental hazards concerning human health. The applications of MNPs are immensely increasing worldwide in different fields like biomedicines, environment, chemistry and material science. Green approaches for the synthesis of NPs is sustainable, eco-friendly, inexpensive and generally free of chemical contaminants. Moreover metal/metaloxides and nanocomposites can be used as photocatalysts for photocatalytic degradation of organic dyes, removal of toxic metals, drugs etc. Hence it is supposed that MNPs can be used in future for environmental remediation and will be helpful in reducing health risk factors. Due to its various physiochemical properties, it will be applicable to interdisciplinary areas. The synthesis of surface functionalized, eco-friendly and cost friendly MNPs will be found applicable in various fields. The surface functionalization of MNPs enhances its stability as well as its properties. Due to its definite size, different crystal structures and large surface area. MNPs are found to exhibit interesting and considerably strong magnetic properties. The optimization of the NPs, size distribution, shapes, coating and agglomeration along with their unique magnetic properties prompted the applications of MNPs in diverse fields. The synthesized material can be used in wastewater treatment such as for the degradation of organic dyes like methylene blue, methyl orange, malachite green, bromophenol blue etc. Removal of heavy toxic metals from water bodies like chromium, arsenic, cadmium, mercury and lead. Apart from its application in wastewater treatment. They can also be applicable in other fields such as sensors for the detection of various biomolecules, analytes etc. The MNPs are highly selective and sensitive and can be used as sensors to various biomolecules like amino acids, vitamins etc. 

 

Highlights

·       The review briefly explains the different methods for synthesis of magnetic nanoparticles and their surface modifications to enhance their properties as well as range of applications.

 

·       It elaborates the various hazards of several dyes and other contaminants present in the water bodies leading to deadly diseases and its remediation by magnetic nanoparticles.

 

·       Study of removal of inorganic and organic contaminants by surface modified magnetic nanoparticles by various removal mechanisms.

 

·       Comparitive study of reusability and recyclability of the different surface modifications of magnetic nanoparticles for wastewater reatment.

 

Acknowledgement

Authors are thankful to Pt. Ravishankar Shukla University Raipur, C.G., India for providing library facilities.

 

REFERENCES

Abba, M., Takahashi, S.M. and Kim, C. (2012). Facile sonochemical synthesis of high moment magnetite (Fe₃O₄) nanocube. J. Nanopart. Res., 15: 1354.

Abdullaera, Z., Omurzak, E., Iwamoto, C., Ganpathy, H.S., Sulaimankhulova, S., Liang, C. and Mashimo, T. (2012). Onion-like carbon-encapsulated Co, Ni, and Fe magnetic nanoparticles with low cytotoxicity synthesized by a pulsed plasma in a liquid. Carbon, 50: 1776-1785.

Ahmad, S., Ali Khan, M.M. and Mohammad, F. (2018). ACS Omega, 3: 9378-9387.

Ahmad, F., Ashraf, N., Ashraf, T., Zhou, R.B. and Yin, C. (2019). Biological synthesis of metallic nanoparticles (MNPs) by plants and microbes: their cellular uptake, biocompatibility, and biomedical applications. Appl. Microbiol. and Biotechnol., 103: 2913-2935.

Ahmed, M.A, Ali, S.M., Dek, S.I.E., Galal, A. (2013). Magnetite–hematite nanoparticles prepared by green methods for heavy metal ions removal from water. Mater. Sci. Eng: B, 178: 744-751.

Akbari, A., Sabouri, Z., Hosseini, H.A., Hashemzadeh, A., Khatami, M. and Darroudi, M. (2020). Effect of nickel oxide nanoparticles as a photocatalyst in dyes degradation and evaluation of effective parameters in their removal from aqueous environments. Inorg. Chem. Commun., 115: 107867.

Alagiri, M., Muthamizhchelvan, C. and  Ponnusamy, S. (2011). Structural and magnetic properties of iron, cobalt and nickel nanoparticles. Synth. Met., 161: 1776-1780.

Albornoz C, Jacobo SE (2006) Preparation of a biocompatible magnetic film from an aqueous ferrofluid. J. Magn. Magn. Mater., 305: 12–15.

Ali, I., Peng, C., Naz, I. and Amjed, M.A. (2019). Water purification using magnetic  Nanomaterials: an overview. Magnetic Nanostructures: Environ. Agri. Applications, 51: 161-179.

Ali, I., Peng, C., Naz, I., Khan, Z.M., Sultan, M., Islam, T. and Abbasi, I.A. (2017). Phytogenic magnetic nanoparticles  for wastewater treatment: A review. RSC Adv., 7: 40158–40178.

Amiri, S. and Shokrollahi, H. (2013). The role of cobalt ferrite magnetic nanoparticles in medical science. Mater. Sci. Eng. C, 33: 1-8.

Andrade, A..L., Souza, D.M., Pereira, M., Fabris, J. and Domingues, R. (2009). Magnetically induced heating by iron oxide nanoparticles dispersed in liquids of different viscosities. Ceram. Int., 55: 420-424.

Arvand, M. and Hemmati, S. (2017). Magnetic nanoparticles embedded with graphene quantum dots and multiwalled carbon nanotubes as a sensing platform for electrochemical detection of progesterone. Sens. Actuators B: Chem., 238: 346-356.

Atta, A.M., Moustafa, Y.M., Lohedan, H.A., Ezzat, A.O. and Hashem, A.I. (2020). Methylene blue catalytic degradation using silver and magnetite nanoparticles functionalized with a poly(ionic liquid) based on quaternized dialkylethanolamine with 2-acrylamido-2- methyl propane sulfonate-co-vinylpyrrolidone. ACS Omega, 5(6): 2829-2842.

Aydin, S., Beduk, F., Ulvi, A. and Aydin, M.E. (2021). Simple and effective removal of psychiatric pharmaceuticals from wastewater treatment plant effluents by magnetite red mud nanoparticles. Sci. Total Environ., 784: 147174.

Bai, L., Du, Y., Peng, J, Liu, Y., Wang, Y., Yang, Y. and Wang, C. (2014). Peptide-based isolation of circulating tumor cells by magnetic nanoparticles. J. Mater. Chem. B, 2: 4080-4088.

Banerjee, S., Benjwal, P., Singh, M. and Kar, K.K. (2018). Graphene oxide (rGO)-metal oxide (TiO₂/Fe₃O₄) based nanocomposites for the removal of methylene blue. Applied Surf. Sci., 439: 560- 568.

Bao, S., Yang, W., Wang, Y., Yu, Y. and Sun, Y. (2020). One-pot synthesis of magnetic graphene oxide composites as an efficient and recoverable adsorbent for Cd (II) and Pb (II) removal from aqueous solution. J. Hazard Mater., 381: 120914.

Bao, Y., Wen, T., Cristina, A., Samia, S., Khandhar, A. and Krishnan, K.M. (2016). Magnetic nanoparticles: material engineering and emerging applications in lithography and biomedicine. J Mater Sci., 51: 513-553.

Behestkhoo, N., Kouhbanani, M.A., Savardashtaki, A., Amani, A.M. and Taghizadeh, S. (2018). Green synthesis of iron oxide nanoparticles by aqueous leaf extract of Daphne mezereum as a novel dye removing material. Appl. Phys A, 124: 1-7.

Berger, R., Kliava, J., Daubric, H. and Estournes, C. (2001). Temperature dependence of superparamagnetic resonance of iron oxide nanoparticles. J. Magn. Magn. Mater., 234: 535-544.

Bradley, M.J., Biacchi, A.J. and Schaak, R.E. (2013). Chemical Transformation of Pt–Fe₃O₄ Colloidal Hybrid Nanoparticles into PtPb–Fe₃O₄ and Pt₃Sn–Fe₃O₄ Heterodimers and (PtPb–Fe₃O₄)_n Nanoflowers. Chem. Mater., 25: 1886-1892.

Bui, T.Q., Ton, S.N., Duong, A. and Tran, H.T. (2018). Dependence of magnetic responsiveness on particle size of magnetite nanoparticles synthesised by co-precipitation method and solvothermal method. J. Sci: Adv. Mater. Devices, 3: 107-112.

Bujnakova, Z., Zorkovska, A. and Kovac, J. (2017). Mechanochemical Preparation and Magnetic Properties of Fe₃O₄/ZnS Nanocomposite. Acta Phys. Pol A, 131: 1120-1122.

Cao, M., Li, Z., Wang, J., Ge, W., Yue, T., Li, R., Colvin, V.L. and Yu, W.W. (2012). Food related applications of magnetic iron oxide nanoparticles: enzyme immobilization, protein purification, and food analysis. Trends Food Sci. Technol., 27: 47-56.

Carvaeho, J., Medeiros, S., Morales, M., Dantas, A. and Carrico, A. (2013). Synthesis of magnetite nanoparticles by high energy ball milling. Appl. Surf. Sci., 275: 84-87.

Chen, F., Xie, S., Huang, X. and Qiu, X. (2017). Ionothermal synthesis of Fe₃O₄ magnetic nanoparticles as efficient heterogenous fenton-like catalyst for degradation of organic pollutants with H₂O_2. J. Hazard. Mater., 322: 152-162.

Chen, H., Li, Y., Wu, H., Sun, N. and Deng, C. (2019). Smart hydrophilic modification of magnetic mesoporous silica with zwitterionic L-cysteine for endogenous glycopeptides recognition. ACS Sustain. Chem. Eng., 7: 2844-285.

Chen, J. and  Zhu, X. (2016). Magnetic solid phase extraction using ionic liquid-coated core–shell magnetic nanoparticles followed by high-performance liquid chromatography for determination of Rhodamine B in food samples. Food Chem., 200: 10-15

Chen, M. and Nikles, D.E. (2002). Synthesis, Self-Assembly, and Magnetic Properties of Fe_xCo_yPt_100-x-y Nanoparticles. Nano Lett., 2: 211-214.

Cheng, Y., Liu, Y., Huang, J., Li, K., Xian, Y., Zhang, W. and Jin, L. (2009). Amperometric tyrosinase biosensor based on Fe₃O₄ nanoparticles-coated carbon nanotubes nanocomposites for rapid detection of coliforms. Electrochimic. Acta, 54: 2588-2594.

Chlebowski, R.T. (1979). Adriamycin (doxorubicin) cardiotoxicity: a review. West. J. Med., 131: 364–368.

Chorny, M., Polyak, B., Alferiev, I.S., Walsh, K., Friedman, G. and Levy, R.J. (2007). Magnetically driven plasmid DNA delivery with biodegradable polymeric nanoparticles. FASEB Jl, 21: 2510– 2519.Choudhury, S.R. and Yanful, E.K. (2013). Kinetics of cadmium (II) uptake by mixed maghemite-magnetite nanoparticles. J. Environ. Manage., 123:  642-651.

Chuiprasert, J., Boontanon, N., Polprasert, C., Ramungul, N., Karawek, A. and Boontanon, S.K. (2024). Ciprofloxacin Electrochemical Sensor Using Copper−Iron MixedMetal Oxides Nanoparticles/Reduced Graphene Oxide Composite. ACS Omega, 9: 23172-23183.

Cole, A.J., David , A.E., Wang, J., Galban, C.J. and Yang V.C. (2011). Magnetic brain tumor targeting and biodistribution of long-circulating PEG-modified, cross-linked starch-coated iron oxide nanoparticles. Biomaterials, 32: 6291-6301.

Cole, A.J., Yang, V.C. and David, A.E. (2011). Cancer theranostics: the rise of targeted magnetic nanoparticles. Trends biotechnol., 29: 323-332.

Cruz, B.D., Madkour, M., Amin, M.O. and Hetlani, E.A. (2020). Efficient and recoverable magnetic AC-Fe₃O₄ nanocomposite for rapid removal of promazine from wastewater. Mater. Chem. Phys., 240: 122109.

Cui, C., He, M., Chen, B. and Hu, B. (2014). Chitosan modified magnetic nanoparticles based solid phase extraction combined with ICP-OES for the speciation of Cr (III) and Cr (VI). Anal. Methods, 6: 8577-8583.

Cui, G., Sun, J., Li, H., Liu, X., Liu, Y., Tian, Y. and Yan, S. (2016). Synthesis and characterization of magnetic elongated hollow mesoporous silica nanocapsules with silver nanoparticles. J. Mater. Chem. A, 4: 1771-1783.

Cui, Y.R., Hong, C., Zhou, Y.L., Li. Y., Zhang, X.X. and Gao, X.M. (2011). Synthesis of orientedly bioconjugated core/shell Fe₃O₄@ Au magnetic nanoparticles for cell separation. Talanta, 85: 1246-1252.

Das, C., Sen, S., Singh, T., Ghosh, T., Paul, S.S., Kim, T.W., Jeon, S., Maiti, D.K., Im, J. and Biswas, G. (2020). Green synthesis, characterization and application of natural product coated magnetite nanoparticles for wastewater treatment. Nanomaterials, 10(8): 1-19.

Djebbi, M.A., Allagui, L., Ayachi, M.S., Boubakri, S., Renault, N.J., Namour, P. and Amara, A.B.H. (2022). Zero valent iron nanoparticles supported on Biomass-Derived Porous Carbon for Simultaneous Detection of Cd²⁺ and  Pb²⁺. ACS Appl. Nano Mater., 5: 546-558

Du, J., Zhang. T., Xing, J.L. and Xu, C.L. (2017). Hierarchical porous Fe₃O₄/Co₃S₄ nanosheets as an efficient electrocatalyst for the oxygen evolution reaction. J. Mater. Chem. A, 5: 9210-9216.

Duan, L., Du, X., Zhao, H., Sun, Y. and Liu, W. (2020). Sensitive and selective sensing system of metallothioneins based on carbon quantum dots and gold nanoparticles. Anal. Chim. Acta., 1125: 177-186.

Đurđić, S.,  Vlahović, F.,  Ognjanović, M.,  Gemeiner,  P.,  Sarakhman,  O., Stanković, V.,  Mutić,  J., Stanković,  D. and  Švorc,   L. (2024). Nano-size cobalt-doped cerium oxide particles embedded  into graphitic carbon nitride for enhanced electrochemical sensing of insecticide fenitrothion. Sci. Total Environ., 909: 168483.

Fall, B., Sall,  D.D.,  Hémadi, M., Karim, A., Diaw, D.,  Fall, M. and Thomas, S. (2023). Highly efficient non-enzymatic electrochemical glucose sensor based on carbon nanotubes functionalized by   molybdenum disulfide and decorated with nickel nanoparticles(GCE/CNT/MoS₂/NiNPs) Sens. Actuators Rep., 5: 100136.

Fatimah, I., Pratiwi, E.Z. and Wicaksono, W.P. (2020). Synthesis of magnetic nanoparticles using parkia speciosa hassk pod extract and photocatalytic activity for Bromophenol blue degradation. Egypt. J. Aquatic Res., 46: 35-40.

Ferrag, C., Noroozifar, M. and Kerman, K. (2023). Ultralight 3D Graphene Oxide Aerogel Decorated with Pd–Fe Nanoparticles for the Simultaneous Detection of Eight Biomolecules. ACS Appl. Mater Interfaces, 15, 23:  27502-27514.

Franzel, L., Bertino, M.F., Huba, Z.J. and Carpenter, E.E. (2012). Synthesis of magnetic nanoparticles by pulsed laser ablation. Appl. Surf. Sci., 261: 332-336.

Gao, S., Zhang, W., Zhou, H. and Chen, D. (2018). Magnetic composite Fe₃O₄/CeO₂ for adsorption of azo dye. J. Rare Earths, 36(9): 986-993.

Garcia, J.A.F., Alavarse, A.C., Maldonado, A.C.M., Cordova, A.T., Ibarra, M.R. and Goya, G.F. (2020). Simple sonochemical method to optimize the heating efficiency of magnetic nanoparticles for magnetic fluid hyperthermia. ACS Omega, 5(41): 26357-26364.

Gautam, K. and Tiwari, I. (2020). Humic acid functionalized magnetic nanomaterials for remediation of dye wastewater under ultrasonication: Application in real water samples, recycling and reuse of nanosorbents. Chemosphere, 245: 125553.

Gill, C.S., Price, B.A. and Jones, C.W. (2007). Sulfonic acid-functionalized silica-coated magnetic nanoparticle catalysts. J. Catal., 251: 145-152.

Granata, C., Russo, R., Esposito, E., Vettoliere, A., Russo, M., Musino, A., Peddis, D. and  Fiorani, D. (2013). Magnetic properties of iron oxide nanoparticles investigated by nanoSQUIDs. The Eur. Phys J. B, 86: 1-5.

Gu, H., Xu, K., Xu, C. and Xu, B. (2006). Biofunctional magnetic nanoparticles for protein separation and pathogen detection. Chemical Commun., 6: 941-949.

Guo, W., Fu, Z., Zhang, Z., Wang, H., Liu, S., Feng, W., Zhao, X. and Giesy, J.P. (2020). Synthesis of Fe₃O₄ magnetic nanoparticles coated with cationic surfactants and their applications in Sb(V) removal from water.  Sci. Total Environ., 710: 136302.

Hammad, A.B.A., Nahwary, A.M.E., Hemdan, B.A. and Abia, A.L.K. (2020). Nanoceramics and novel functionalized silicate-based magnetic nanocomposites as substitutional disinfectants for water and wastewater purification. Environ. Sci. Pollut. Res., 27: 26668-26680.

Harkness, K.M., Cliffel, D.E. and Mclean, J.A. (2010). Characterization of thiolate-protected gold nanoparticles by mass spectrometry. Analyst, 135: 868-874.

Hasanpour, A., Mozaffai, M. and Amighian, J. (2007). Preparation of Bi–Fe₃O₄ nanocomposite through reduction of Bi₂O₃ with Fe via high-energy ball milling. Phys. B: Condens Matter, 387: 298-301.

Hasanzadeh, M., Karimzadeh, A. and Shadjou, N. (2016). Synthesis, electrodeposition, characterization and application as an electrochemical sensor towards determination of some amino acids at physiological pH. Mater. Sci. and Eng.: C, 68: 814-830.

Hasanzadeh, M., Shadjou, N. and Guardia, M.D. (2015). Iron and iron-oxide magnetic nanoparticles as signal-amplification elements in electrochemical biosensing. Trends Anal. Chem., 72: 1-9.

He, Q., Liu, J., Liang, J., Liu, X., Tuo, D. and Li, W. (2018). Chemically surface tunable solubility parameter for controllable drug delivery-an example and perspective from hollow PAA-coated magnetite nanoparticles with R6G model drug. Materials, 11: 247–263.

He, X., Liu, Q. and Xu, Z. (2020). Treatment of oily wastewaters using magnetic Janus nanoparticles of asymmetric surface wettability. J. Colloid Interface Sci., 568: 207-220.

Heidari, A., Mir, N. and Nikkaran, A.R. (2016). Phenylalanine removal from water by Fe₃O₄ nanoparticles functionalized with two different surfactants. J. Nanostruct., 6: 199-206.

Hong, R.Y., Pan, T.T., Han, Y.P., Li, H.Z., Ding, J. and Han, S. (2007). Magnetic field synthesis of Fe₃O₄ nanoparticles used as a precursor of ferrofluids. J. Magn. Magn. Mater., 310: 37-47.

Huang, L., Luo, F., Chen, Z., Megharaj, M. and Naidu, R. (2015). Green synthesized conditions impacting on the reactivity of Fe NPs for the degradation of malachite green. Spectrochim. Acta A: Mol. Biomol. Spectrosc., 137: 154-159.

Huang, Y. and Keller, A.A. (2015). EDTA functionalized magnetic nanoparticle sorbents for cadmium and lead contaminated water treatment. Water Res., 80: 159-168.

Huang, Q., Liu, Y., Zhang, C., Zhang, Z., Liu, F. and Peng, J. (2020). Au quantum dot/ nickel Tetraminophthalocyanaine− GrapheneOxide-Based Photoelectrochemical Microsensor for Ultrasensitive Epinephrine Detection. ACS Omega, 5: 8423-8431.

Huang, Y. and Keller, A. A. (2013). Magnetic nanoparticle adsorbents for emerging organic contaminants. ACS Sustainable Chem. Eng., 1, 7: 731-736.

Hyeon, T. (2003). Chemical synthesis of magnetic nanoparticles. Chem. Comm., 8: 927-934.

Jadhav, V., Chikode, P., Nikam, G. and Sabale, S. (2016). Polyol synthesis and characterization of ZnO@CoFe₂O₄ MNP’s to study the photodegradation rate of azo and diphenyl type dye. Mater. Today: Proc., 3: 4121-4127.

Jiaqi, Z., Yimin, D., Danyang, L., Shergyun, W., Liling, Z. and Yi, Z. (2019). Synthesis of carboxyl-functionalized magnetic nanoparticle for the removal of methylene blue. Colloids and Surf. A: Physiochem. Eng. Asp., 572: 58-66.

Jin, Y., Liu, F., Shan, C., Tong, M. and Hou, Y. (2014). Efficient bacterial capture with amino acid modified magnetic nanoparticles. Water Res., 50: 124-134.

Joshi, N., Filip, J., Coker, V.S., Sadhukhan, J., Safarik, I., Bagshaw, H. and Lloyd, J.R. (2018). Microbial reduction of natural Fe (III) minerals; towards the sustainable production of functional magnetic nanoparticles. Front. Environl. Sci., 127: 556-578.

Jouyandeh, M., Paran, S.M.R., Shabanian, M., Ghiyasi, S., Vahabi, H., Badawi, M., Formela, K.,  Puglia, D. and Saeb, M.R. (2018). Curing behavior of epoxy/Fe₃O₄ nanocomposite: A comparision between the effects of bare Fe₃O₄, Fe₃O₄/SiO₂/chitosan and Fe₃O₄/SiO₂/chitosan /imide/phenylalanine-modified nanofillers. Prog. Organic Coatings, 123: 10-19.

Jung, J.H. and Shinkai, S. (2011). Functionalized magnetic nanoparticles as chemosensors and adsorbents for toxic metal ions in environmental and biological fields. Chem. Soc. Rev., 40: 4464-4474.

Katepetch, C. and Rujiravanit, R. (2011). Synthesis of magnetic nanoparticle into bacterial cellulose matrix by ammonia gas-enhancing in situ co-precipitation method. Carbohydr. Polym., 86: 162-170.

Khan. S., Naushad, M., Gheethi, A.A. and Iqbal, J. (2021). Engineered nanoparticles for removal of pollutants from wastewater: Current status and future prospects of nanotechnology for remediation strategies. J. Environ. Chem. Eng., 9(5): 106160.

Kheilkordi, Z., Ziarani, G.M., Mohajer, F., Badiei, A. and Sillanpaa, M. (2022). Recent advances in the application of magnetic bio-polymers as a catalyst in multi component reactions. RSC Adv., 12: 12672-12701.

Khodadadi, M., Musawi, T.J.A., Kamani, H., Silva, M.F., Panahi, A.H. (2020). The practical  utility of the synthesis FeNi₃@ SiO₂@ TiO₂ magnetic nanoparticles as an efficient photocatalyst for the humic acid degradation. Chemosphere, 239: 124723.

Kim, D.H., Vitol, E.A., Liu, J., Balasubramanian, S., Gosztola, D.J., Cohen, E.E., Novosad, V. and Rozhkova, E.A. (2013). Stimuli-responsive magnetic nanomicelles as multifunctional heat and cargo delivery vehicles. Langmuir, 29: 7425–7432.

Koventhan, C., Shanmugam, R. and Chen, S.M. (2023). Development of highly sensitive electrochemical   sensor for antipsychotic drug perphenazine using perovskite structured lanthanum cobalt oxide nanoparticles wrapped graphitic carbon nitride nanocomposites. Electrochim. Acta, 467: 143096.

Kreissel, P. and Holm, W. (2021). Frequency-dependent magnetic susceptibility of magnetic nanoparticles in a polymer solution: a simulation study. Soft Matter., 17: 174-183.

Kroll, E., Winnik, F.M. and Ziolo, R.F. (1996). In Situ Preparation of Nanocrystalline γ-Fe₂O₃ in Iron(II) Cross-Linked Alginate Gels. Chem. Mater, 8: 1594–1596.

Kumar, P.K., Krishna, S.V., Verma, K, Pooja, K., Bhagawan, D. and Himabindu, V. (2018). Phycoremediation of sewage wastewater and industrial flue gases for biomass generation from microalgae. S. Afr. J. Cheml. Eng., 25: 133-146.

Kumari, M. and Gupta, S.K. (2020). A novel process of adsorption cum  enhanced coagulation flocculation spiked with magnetic  nanoadsorbents  for  the removal of aromatic and hydrophobic fraction of natural  organic  matter along with turbidity from drinking water. J. Clean Prod., 244: 118899.

Kurlyandskaya, G.V., Beitia, I.M., Beketov, I.V., Medvedev, A.I., Larranaga, A., Safronov, A.P. and Bhagat, S.M.  (2014). Structure, magnetic and microwave properties of FeNi nanoparticles obtained by electric explosion of wire. J. Alloys Compd., 615: 231-235.

Li, J., Gong, A., Li, F., Qiu, L., Zheng, W., Gao, G., Liu, Y. and Li, J. (2018). Synthesis and characterization of magnetic mesoporous Fe₃O₄@ mSiO 2–DODGA nanoparticles for adsorption of 16 rare earth elements. RSC Adv., 8: 39149-39161.

Li, J., Guo, L.T., Shangguan, E., Yue, M.Z., Xu, M., Wang, D., Chang, Z.R. and Li, Q.M. (2017). Synthesis of novel spherical Fe₃O₄@ Ni₃S₂ composite as improved anode material for rechargeable nickel-iron batteries. Electrochim. Acta., 240: 456-465.

Li, W., Ma, Y., Guo, Z., Xing, R. and Liu, Z. (2020). Efficient screening of glycan-specific aptamers using a glycosylated peptide as a scaffold. Anal. Chem., 93: 956-963.

Li, Z., Xu, S., Xiao, G., Qian, L. and Song, Y. (2019). Removal of hexavalent chromium from groundwater using sodium alginate dispersed nano zero-valent iron. J. Environ. Manag., 244: 33-39.

Li, Z., Xu, S. Removal of hexavalent chromium from groundwater using sodium alginate dispersed nano zero-valent iron. J. Environ. Manage., 244: 33-39.

Lin, X.M. and Samia, A.C. (2006). Synthesis, assembly and physical properties of magnetic nanoparticles. J. Magn. Magn. Mater., 305: 100-109.

Liu, Y., Zhang, B. and Yan, B. (2011). Enabling anticancer therapeutics by nanoparticle carriers: the delivery of Paclitaxel. Int. J. Mol. Sci., 12: 4395–4413.

Low, L.E., Tey, B.T., Oong, B.H. and Tang, S.Y. (2018). A facile and rapid sonochemical synthesis of monodispersed Fe₃O₄@cellulose nanocrystals nanocomposites without inert gas protection. Asia Pacific J. Chem. Eng., 13: 1-16.

Lu, T., Qi, D., Zhang, D., Fu, K., Li, Y. and Zhao, H. (2020). Fabrication of recyclable multi-responsive magnetic nanoparticles for emulsified oil-water separation. J. Clean. Prod., 255: 120293.

Luo, S., Zheng, X. and Cheng, J.P. (2008). Asymmetric bifunctional primary aminocatalysis on magnetic nanoparticles. Chem. Comm., 44: 5719-5721.

Lyon, J.L., Fleming, D.A., Stone, M.B., Schiffer, P. and Williams, M.E. (2004). Synthesis of Fe oxide core/Au shell nanoparticles by iterative hydroxylamine seeding. Nano Lett., 4: 719–723.

Ma, Z., Shan, C., Liang, J. and Tong, M. (2018). Efficient adsorption of Selenium (IV) from water by hematite modified magnetic nanoparticles. Chemosphere, 193: 134-141.

Macdonald, J.E. and Veinot,  J.G.C. (2008). Removal of residual metal catalysts with Iron/ iron oxide nanoparticles from coordinating environments. Langmuir, 24: 7169-7177.

Mahmoudi, M., Simchi, A., Milawi, A.S. and Stroeve, P. (2009). Cell toxicity of superparamagnetic iron oxide nanoparticles. J. of Colloid Interface Sci., 336: 510-518.

Maiti, A. (2020). Cobalt-based heterogeneous catalysts in an electrolyzer system for sustainable energy storage. Dalton Trans., 49: 11430-11450.

Majidi, S., Sehrig, F.Z., Farkhani, S.M., Goloujeh, M.S. and Akbarzadeh, A. (2016). Current method for synthesis of magnetic nanoparticles. Nanomed. Biotechnol., 44: 722–734.

Maleki, B. and Esmaeili, H. (2023). Application of Fe₃O₄/SiO₂@ZnO magnetic composites as a recyclable heterogeneous nanocatalyst for biodiesel production from waste cooking oil: Response surface methodology. Ceram. Int., 49: 11452-11463.

Maltas, E., Ozmen, M., Vural, H.C., Yildiz, S. and Ersoz, M. (2011). Immobilization of albumin on magnetite nanoparticles. Mater. Lett., 65: 3499-3501.

Marcus, M., Smith, A., Maswadeh, A., Shemesh, Z., Zak, I., Motiei, M., Schori, H., Margel, S., Sharoni, A. and Shefi, O. (2018). Magnetic targeting of growth factors using iron oxide nanoparticles. Nanomaterials, 8: 707-724.

Mcbain, S.C., Yiu, H.H.P., El. Haj, A. and Dobson, J. (2007). Polyethyleneimine functionalized iron oxide nanoparticles as agents for DNA delivery and transfection. J. Mater. Chem., 17: 2561-2565.

Mdlovu, N.V., Lin, K.S., Mavuso, F.A. and Weng, M.T. (2020). Preparation, characterization and in-vitro studies of doxorubicin-encapsulated silica coated iron oxide nanocomposites on liver cancer cells. J. Taiwan Institute of Chem. Eng., 117: 190-197.

Meenach, S.A., Hilt, J.Z. and Anderson, K.W. (2010). Poly (ethylene glycol)-based magnetic hydrogel nanocomposites for hyperthermia cancer therapy. Acta Biomater., 6: 1039–1046.

Menon, S., Dutta, S., Madaboosi, N. and Sai, V.V.R. (2024). Cobalt-Doped ZIF-8 Nanoparticle-Decorated Fiber Optic Sensor for Copper Ion Detection. ACS Appl. Nano Mater., 7: 18346-18356

Mohammed, L., Gomma, H.G., Ragal, D. and Zhu, J. (2017). Magnetic nanoparticles for environmental and biomedical applications: A review. Particuology, 30: 1-14.

Mollarasouli, F., Zor, E., Ozcelikay, G. and Ozkan, S.A. (2021). Magnetic nanoparticles in developing electrochemical  sensors for pharmaceutical and biomedical applications. Talanta, 226: 122108.

Moradina, F., Fardood, S.T., Ramazani, A., Min, B.K., Joo, S.W. and Varma, R.S. (2021). Magnetic Mg_0.5Zn_0.5FeMnO₄ nanoparticles: Green sol-gel synthesis, characterization and photocatalytic applications. J. Clean Prod., 288: 125632.

Mourdikoudis, S., Pallares, R.M. and Than, N. (2018). Characterizations techniques for nanoparticles: comparision and complementarity upon studying nanoparticles. Nanoscale, 10: 12871-12934.

Nawara, K., Romiszewski, J., Kijajiwska, K., Sjczytko, J., Twardowski, A., Mazur, M. and Krysinski, P. (2012). Adsorption of doxorubicin onto citrate stabilized magnetic nanoparticles. The J. Phys. Chem. C, 116: 5598-5609.

Nejad, S.B. and Mohammadi, A. (2020). Epoxy-Triazinetrione-Functionalized Magnetic Nanoparticles as an Efficient Magnetic Nanoadsorbent for the Removal of Malachite Green and Pb(II) from Aqueous Solutions. J. Chem. Eng. Data, 65: 2731-2742.

Nigam, S., Barick, K.C. and Bahadur, D. (2011). Development of citrate-stabilized Fe₃O₄ nanoparticles: conjugation and release of doxorubicin for therapeutic applications. J. Magn. Magn. Mater., 323: 237–243.

Nordin, A.H., Wong, S., Ngadi, N., Zainol, M.M., Latif, N.A.F.A. and Nabgan, W. (2021). Surface functionalization of cellulose with polyethyleneimine and magnetic nanoparticles for efficient removal of anionic dye in wastewater. J. Environ. Chem. Eng., 9: 104639.

Othman, N.H., Alias, N.H., Shahruddin, M.Z., Bakar, N.F.A., Him, N.R.N. and Lau, W.J. (2018). Adsorption kinetics of methylene blue dyes onto magnetic graphene oxide. J. Environ. Chem. Eng., 6: 2803-2811.

Ozel, F. and Kochkar, H. (2015). Growth and characterizations of magnetic nanoparticles under hydrothermal conditions: Reaction time and temperature. J. Magn. Magn. Mater., 373: 213-216.

Pandya, S.R. and Singh, M. (2016). Preparation and characterization of magnetic nanoparticles and their impact on anticancer drug binding and release processes moderated through a 1^st tier dendrimer. RSC Adv., 6: 37391-37402.

Park, I.K., Ng, C.P., Wang, J., Chu, B., Yuan, C., Zhang, S. and Pun, S.H. (2008). Determination of nanoparticle vehicle unpackaging by MR imaging of a T2 magnetic relaxation switch. Biomaterials, 29: 724– 732.

Pepping, J. (1999). Complementary and integrative approaches to dementia. Am. J. Health Syst. Pharm., 56: 1195-1198.

Peralta, M.E., Martire , D.O., Moreno, M.S., Parolo, M.E. and Carlos, L. (2021). Versatile nanoadsorbent based on magnetic mesostructured silica nanoparticles with tailored surface properties for organic pollutants removal. J. Environ. Chem. Eng., 9: 104841.

Perez, J.A.L., Quintela, M.A.L., Mira, J., Rivas, J. and Charles, S.W. (1997). Advances in the preparation of magnetic nanoparticles by the microemulsion method. J. Phys. Chem. B, 101: 8045-8047.

Poonguzhali, R.V.,  Ranjith, Kumar, E , Ch. Srinivas,  Alshareef,  M.,  Aljohani,  M.M.,  Keshk,  A.A., Metwaly, N.M. and Arunadevi, N. (2023). Natural lemon extract assisted green synthesis for LPG Sensor.  Sens. Actu. B: Chem.,  377: 133036.

Prasad, C., Gangadhara, S. and Venkateswarlu, P. (2016). Bio-inspired green synthesis of Fe₃O₄ magnetic nanoparticles using watermelon rinds and their catalytic activity. App. Nanosci., 6: 797-802.

Predescu, E.C. , Predescu, A. and Ficai, D. (2015). The effect of Si content on ferrihydrite sorption capacity for Pb (II), Cu (II), Cr (VI), and P (V). Environ. Eng. Manag. J., 14(5): 1001.

Qiao, Y., Yao, Z., Wang, X., Zhang, X., Bai, C., Li, Q., Chen, K., Li, Z. and Zheng, T. (2020). Lattice composites with embedded short carbon fiber/Fe₃O₄/epoxy hollow spheres for structural performance and microwave absorption. Mater. Des., 188: 108427.

Rajiv, P., Bavadharani, B., Kumar, M.N. and Vanathi, P. (2017). Synthesis and characterization of biogenic iron oxide nanoparticles using green chemistry approach and evaluating their biological activities. Biocatal. and Agric. Biotechnol., 12: 45-49.

Rana, S., Shetake, N.G., Barick, K.C., Pandey, B.N., Salunke, H.G. and Hassan, P.A. Folic acid conjugated Fe₃O₄ magnetic nanoparticles for targeted delivery of doxorubicin. Dalton Trans., 45: 17401-17408.

Rasouli, K., Alamdari, A. and Sabbagh, S. (2023). Ultrasonic-assisted synthesis of α-Fe₂O₃@TiO₂ photocatalyst: Optimization of effective factors in the fabrication of photocatalyst and removal of non-biodegradable cefixime via response surface methodology-central composite design. Sep. Purif. Technol., 307: 122799.

Rathan Kumar, A.K., Saikia, K., Neeraj, G., Cabana, H. and Kumar, V.V. (2020). Remediation of  biorefinery wastewater containing organic and inorganic toxic pollutants by adsorption onto  chitosn-based magnetic nanoadsorbent. Water Qual. Res. J., 55(1): 36-51.

Reddy, C.V., Reddy, I.N., Ravindranadh, K., Reddy, K.R., Shetti, N.P., Kim, D., Shim, J. and Aminabhavi, T.M. (2020). Copper-doped ZrO₂ nanoparticles as high-performance catalysts for efficient removal of toxic organic pollutants and stable solar water oxidation. J. Environ. Manag., 260: 110088.

Reziq, R.A., Alper, H., Wang, D. and Post, M.L. (2006). Metal supported on dendronized magnetic nanoparticles: highly selective hydroformylation catalysts. J. Am. Chem. Soc., 128: 5279-5282.

Rodriguez, A.F., Moya, C., Toroella, M.E., Romero, A., Labarta,  A. and Batlle, X. (2018). The role of cobalt ferrite magnetic nanoparticles in medical science. J. Mater. Chem. C, 6: 875-882.

Roy, A. and Bhattacharya, J. (2012). Removal of Cu (II), Zn (II) and Pb (II) from water using microwave-assisted synthesized maghemite nanotubes. Cheml. Eng. J., 211: 493-500.

S. Islam, M. A. Raza and S. Naseem, (2020). Ceramic Inter., 46: 1942-1951.

Sahu, D., Pervez, S., Karbhal, I., Tamrakar, A., Mishra, A., Verma, S.R., Deb, M.K., Ghosh, K.K., Pervez, Y.F., Shrivas, K., Satnami, M.L. (2024). Applications of different adsorbent materials for the removal of organic and inorganic contaminants from water and wastewater-A review. Desalin. Water Treat., 317: 100253.

Salabat, A. and Mirhoseini, F. A (2018). Novel and simple microemulsion method for synthesis of biocompatible functionalized gold nanoparticles. J. Mol. Liq., 268: 849–853.

Santos, T.A.P. (2014). Sensors and biosensors based on magnetic nanoparticles. Trends Anal. Chem., 62: 28-36.

Sapsford, K.E., Algar, W.R., Berti, L., Gemmill, K.B., Casey, B.J., Oh, E., Stewart, M.H., and Medintz, I.L. (2013). Functionalizing nanoparticles with biological molecules: developing chemistries that facilitate nanotechnology. Chem. Rev., 113: 1904–2074.

Shafaei, S. and Sharafian, S. (2019). Green Synthesis of Imidazole Derivatives via Fe₃O₄‐MNPs as Reusable Catalyst. J. of Heterocycl. Chem. 56: 2644-2650.

Shankar, U., Kumar, A., Chaurasia, S.K., Kumar, P., Latif, F.A. and Yahya, M.Z.A. (2023). Structural, Optical, and Magnetic Properties of PMMA-Magnetite (Fe₃O₄) Composites: Role of Magneto-Conducting Filler Particles. J. Electron Mater., 52(7): 4375-4387.

Sharma, R.K., Yadav, S., Gupta, R. and Arora, G. (2019). Synthesis of magnetic nanoparticles using potato extract for dye degradation: A green chemistry experiment. J. Chem. Ed., 96: 3038-3044.

Shukla, S., Khan, R. and Daverey, A. (2021). Synthesis and characterization of magnetic nanoparticles, and their applications in wastewater treatment: A review. Environ. Technol. Innov., 24: 101924.

Singer, N., Pillai, R.G., Johnson, A.D., Harris, K.D. and Jemere, A.B. (2020). Nanostructured nickel oxide electrodes for non-enzymatic electrochemical glucose sensing. Michrochim. Acta., 187:12346

Sivakami, S., Renuka Devi, K., Renuka, R. and Thilagavathi, T. (2020). Green synthesis of magnetic nanoparticles via cinnamomum verum bark extract for biological application. J. Environ. Chem. Eng., 8: 104420.

Soshnikova, Y.M., Roman, S.G., Chebotareva, N.A., Baum, O.I., Obrezkova, M.V., Gillis, R.B., Harding, S.E., Sobol, E.N. and Lunin, V.V. (2013). Starch modified magnetite nanoparticles for impregnation into cartilage. Journal of Nanopart. Res., 15: 2092-2098.

Sun, X., Ma, G., Lv, X., Sui, M., Li, H., Wu, F. and Wang, J. (2018). Controllable fabrication of Fe₃O₄/ZnO core-shell nanocomposites and their electromagnetic wave absorption performance in the 2-18GHz frequency range. Materials, 11: 780.

Sun, Y.K, Ma, M., Zhang, Y. and Gu, N. (2004). Synthesis of nanometer-size maghemite particles from magnetite. Colloids Surf. A: Physiochem. Eng. Asp., 245: 15-19

 

Swihart, M.T. (2003). Vapor-phase synthesis of nanoparticles, Curr. Opin. Colloid Interface Sci., 8: 127-133.

Tartaj, P., González-Carreño, T. and Serna, C.J. (2001). Single‐step nanoengineering of silica coated maghemite hollow spheres with tunable magnetic properties. Adv. Mater., 13: 1620–1624.

Tiefenauer, L.X., Kuhne, G. and Andres, Y.R. (1993). Antibody-magnetite nanoparticles: in vitro characterization of a potential tumor-specific contrast agent for magnetic resonance imaging. Bioconjug. Chem., 4: 347-352.

Tonghan, G., Zhang, Y., Khan, S.A. and Hatton, T.A. (2019). Continuous flow synthesis of superparamagnetic nanoparticles in reverse miniemulsion systems. Colloids Interface Sci. Commun., 28: 1-4.

Uzunoğlu, D. and Özer, A. (2022). Facile Synthesis of Magnetic Iron-Based Nanoparticles from the Leach Solution of Hyperaccumulator Plant Pinus brutia for theAntibacterial Activity and Colorimetric Detection of Ascorbic Acid. ACS Appl. Bio Mater., 5: 5465-5476.

Vojoudi, H., Badiei, A., Banaei, A. , Bahar, S., Karimi, S., Ziarani, G.M. and Ganjali, M.R. (2017). Extraction of gold, palladium and silver ions using organically modified silica-coated magnetic nanoparticles and silica gels as a sorbent. Microchim. Acta., 184: 3859-3866.

Wagener, M. and Ther, B.G. (1999). Sputtering on liquids–a versatile process for the production of magnetic suspensions? J. Magn. Magn. Mater., 201: 41-44.

Wang, J., Wu, X., Wang, C., Rong, Z., Ding, H., Li, H., Li, S., Shao, N., Dong, P., Xiao, R. and Wang, S. (2016). Facile synthesis of Au-coated magnetic nanoparticles and their application in bacteria detection via a SERS method. ACS Appl. Mater Interfaces, 8: 19958-19967.

Wang, R., Wan, Y., He, F., Qi, Y., You, W. and Luo, H. (2012). The synthesis of a new kind of magnetic coating on carbon fibers by electrodeposition. Appl. Surf. Sci., 58: 3007-3011.

Wang, S., Bao, H., Yang, P. and Chen, G. (2008). Immobilization of trypsin in polyaniline-coated nano-Fe₃O₄/carbon nanotube composite for protein digestion. Anal. Chim. Acta., 612: 182-189.

Wang, W., Xiao, X., Chen, J. and Jia, L. (2015). Carboxyl modified magnetic nanoparticles coated open tubular column for capillary electrochromatographic separation of biomolecules. J. Chromatogr. A, 1411: 92-100.

Wang, Y., Dostalek, J. and Knoll, W. (2011). Magnetic nanoparticle-enhanced biosensor based on grating-coupled surface plasmon resonance. Anal. Chem., 83: 6202-6207.

Wang, Y., Li, J. and Wei, Z. (2018). Transition-metal-oxide-catalyst for oxygen reduction reactions. J. Mater. Chem. A, 6: 8194-8209.

Wang, Y., Pan, J.A., Wu, H. and Talapin, D.V. (2019). Direct wavelength-selective optical and electron-beam lithography of functional inorganic nanomaterials. ACS Nano, 13: 13917-13931.

Wei, Y., Han, B., Hu, X., Lin, Y., Wang, X. and Deng, X. (2012). Synthesis of Fe₃O₄ nanoparticles and their magnetic properties. Procedia Eng., 27: 632-637.

Weng, X., Huang, L., Chen, Z., Meghraj, M. and Naidu, R. (2013). Synthesis of iron based nanoparticles by green tea extract and their degradation of malachite. Ind. Crops Prod., 51: 342-347.

Weteskog, E., Castro, A., Zeng, L., Petronis, S., Heinke, D., Olsson, E., Nilsson, L., Gehrke, N. and Snedlindh, P. (2017). Size and property bimodality in magnetic nanoparticle dispersions: single domain particles vs. strongly coupled nanoclusters. Nanoscale, 9: 4227-4235.

Wierucka, M. and Biziuk, M. (2014). Application of magnetic nanoparticles for magnetic solid-phase extraction in preparing biological, environmental and food samples. Trends Anal. Chem., 59: 50-58.

Wu, R., Liu, J.H., Zhao, L., Zhang, X., Xie, J., Yu, B., Ma, X., Yang, S.T., Wang, H. and Liu, Y. (2014). Hydrothermal preparation of magnetic Fe₃O₄@ C nanoparticles for dye adsorption. J. Environ. Chem. Eng., 2(2): 907-913.

Wulandari, O., Santjojo, D.J.D.H., Shobirin, R.A. and Sabarudin, A. (2017). Characteristics and magnetic properties of chitosan-coated Fe₃O₄ nanoparticles prepared by ex-situ co-precipitation method. Rasayan J. Chem., 10(4): 1348-1358.

Xia, L.Y., Zhang, M.Q., Yuan, C. and Rong, M.Z. (2011). A facile heteroaggregate-template route to hollow magnetic mesoporous spheres with tunable shell structures. J Mater. Chem., 21: 9020–9026.

Xu, J., Yang, H., Fu, W., Du, K., Sui, Y., Chen, J., Zeng, Y., Li, M. and  Zou, G. (2007). Preparation and magnetic properties of magnetite nanoparticles by sol–gel method. J. Magn. Magn. Mater., 309: 307-311.

Xue, B. and Sun, Y. (2001). Protein adsorption equilibria and kinetics to a poly (vinyl alcohol)-based magnetic affinity support. J. Chromatogr. A, 921: 109–119.

Yang, H., Jang, S., Hong, S., Lee, K., Roh, C., Luh, Y. and Seo, B. (2016). Prussian blue-functionalized magnetic nanoclusters for the removal of radioactive cesium from water. J. Alloys Compd., 657: 387-393.

Yang, T. and Cong, H.L. (2019). Analysis of factors affecting preparation of magnetic Fe₃O₄@PS nanospheres. Integr. Ferroelectr., 198: 137-141.

Yin, L., Liu, L., Lin, S., Owens, G. and Chen, Z. (2022). Synthesis and characterization of Nanoscale Zero-Valent Iron (nZVI) as an adsorbent for the simultaneous removal of As (III) and As (V) from groundwater. J. Water Proc. Engineering, 47: 102677.

You, J., Wang, L., Zhao, Y. and Bao, W. (2021). A review of amino-functionalized magnetic nanoparticles for water treatment: Features and prospects. J. Clean. Prod., 281: 124668.

Yuvakkumar, R. and Hong, S. (2014). Green synthesis of spinel magnetite iron oxide nanoparticles. Adv. Mater. Res., 1051: 39-42.

Zamay, G.S., Zamay, T.N., Lukyanenko, K.A. and Kichkailo, A.S. (2020). Aptamers increase biocompatibility and reduce the toxicity of magnetic nanoparticles used in biomedicine. Biomedicines, 8: 59-72.

Zhang, L., Wu, Z., Chen, L., Zhang, L., Li, X., Xu, H., Wang, H. and Zhu, G. (2016). Preparation of magnetic Fe₃O₄/TiO₂/Ag composite microspheres with enhanced photocatalytic activity. Solid State Sci., 52: 42-48.

Zhang, M., Du, H., Wei, Z., Zhang, X. and Wang, R. (2021). Facile electrodeposition of Mn-CoP nanosheets on Ni foam as high-rate and ultrastable electrodes for supercapacitors. ACS Appl. Energy Mater., 5: 186-195.

Zhang, X., Chen, L., Liu, R., Li, D., Ge, X. and Ge, G. (2019). The Role of the OH Group in Citric Acid in the Coordination with Fe₃O₄ Nanoparticles. Langmuir, 35: 8325-8332.

Zhang, Z. and Wen, G. (2020). Synthesis and characterization of carbon-encapsulated magnetite, martensite and iron nanoparticles by high-energy ball milling method. Mater. Charact., 167: 110502.

Zuluaga, J.M., Restrepo, J. and Lopez, J.M. (2007). Surface anisotropy of a Fe₃O4 nanoparticle: A simulation approach. Phys B: Condens. Matter, 398: 187-190.