Fe3O4 Magnetic Nanocomposites Research Articles

Fabrication of magnetic carbohydrate-modified iron oxide nanoparticles (Fe3O4/pectin) decorated with bimetallic Co/Cu-MOF as an effective and recoverable catalyst for the Biginelli reaction.

Due to their biocompatibility, facile recoverability, mechanical and thermal stability, high surface area, and active catalytic sites, magnetic nanocomposites, containing natural polymers and magnetic nanoparticles, have been used to produce supports for catalysts or biocatalysts. Pectin, an important polycarbohydrate, has abundant functional groups with excellent ability to coat the surface of the nanoparticles to fabricate composite and hybrid materials. A novel bimetallic cobalt(ii) and copper(ii)-based metal-organic framework (Co/Cu-MOF) immobilized pectin-modified Fe3O4 magnetic nanocomposite was designed and fabricated. Fe3O4 nanoparticles were modified in situ by pectin and, subsequently, used as a support for growing Co/Cu-MOF [Fe3O4/pectin/(Co/Cu)MOF]. The properties of the nanocomposite were investigated by FT-IR, XRD, SEM, EDS, VSM, STA, and BET. The nanocomposite exhibited both magnetic characteristics and a high surface area, making it a suitable candidate for catalytic applications. Then, the Fe3O4/pectin/(Co/Cu)MOF nanocomposite was utilized in the Biginelli reaction for the production of biologically active dihydropyrimidinones. Due to paramagnetism, Fe3O4/pectin/(Co/Cu)MOF was easily recovered and reused in six cycles without significant loss in reactivity. This green method comprises several benefits, such as mild reaction conditions, free-solvent media, high yields, easy workup, short reaction times and reusability of the prepared catalyst.

Sustainable conversion of carbon dioxide into novel 5-aryldiazenyl-1,2,4-triazol-3-ones using Fe3O4@SP-vanillin-TGA nanocomposite

Abstract A series of novel 5-aryldiazenyl-1,2,4-triazol-3-ones are synthesized at room temperature in short reaction time, and excellent yields via four-component reaction between 4-aryldiazenyl-salicylaldehydes, ammonium acetate, arylhydrazine, and carbon dioxide using bis(thioglycolic acid)-vanillin (2,2′-(((4-hydroxy-3-methoxyphenyl)methylene)bis(sulfanediyl))diacetic acid)‐functionalized silica-coated Fe3O4 magnetic nanocomposite (Fe3O4@SP-vanillin-TGA MNCs). The present protocol offers several advantages such as gentle reaction conditions, excellent performance, simple fabrication, separation methods, and reduction of detrimental environmental consequences. The catalyst could be easily recovered and reused for six runs with nearly steady activity. The structures of the synthesized 5-aryldiazenyl-1,2,4-triazol-3-ones have been confirmed with the aid of using 1H, 13C NMR, and fourier transform infrared spectral data and elemental analyses.

Green Synthesis, Characterization and Application of Proanthocyanidins-Functionalized Fe3O4 Magnetic Nanocomposites

In this study, proanthocyanidins-functionalized Fe3O4 magnetic nanocomposites were synthesized by the hydrothermal method. The prepared Fe3O4 nanocomposites were characterized by Fourier transform infrared spectrometer (FTIR), X-ray powder diffractometer (XRD), physical property measurement system (PPMS), particle size analyzer, scanning electron microscope (SEM), and transmission electron microscope (TEM). FTIR results indicated that the obtained products were coated with proanthocyanidins. The SEM and TEM results, as well as particle size distribution analysis, revealed that the obtained products were spherical particles with average diameter of [Formula: see text][Formula: see text]nm. XRD and PPMS characterization confirmed that the Fe3O4 nanoparticles have a cubic spinel structure with magnetic properties. The performance of the Fe3O4 nanocomposites for removing organic dyes in an aqueous solution was investigated. The synthesized products were found to be effective on removing various organic dyes, such as Methylene blue (MB), neutral red (NR) and Rhodamine B (RhB), indicating their considerable potential as efficient dyes adsorbents for wastewater treatment.

Determination of Sulfadiazine in Natural Waters by Pine Needle Biochar – Derivatized Magnetic Nanocomposite Based Solid-Phase Extraction (SPE) with High-Performance Liquid Chromatography (HPLC)

A magnetic solid-phase extraction (MSPE) method was developed for the facile and sensitive determination of sulfadiazine prior to high-performance liquid chromatography (HPLC) analysis. The magnetic sorbent was prepared by the chemical co-precipitation of Fe3O4 magnetic nanocomposites modified with biochar. Characterization of the synthesized Fe3O4@BC-PN (Fe3O4 loaded pine leaves derived biochar) was performed by scanning electron microscopy – energy dispersive x-ray spectrometry (SEM-EDS), X-ray diffraction (XRD), vibrating sample magnetometry (VSM), and Brunauer – Emmett – Teller (BET) surface analysis. The saturation magnetization value was 17.95 emu/g by vibrating sample magnetometry. The Fe3O4@BC-PN particle sizes were determined to be 11.8 nm using the Debye-Scherrer relationship. The pH, mass of adsorbent, type, and volume of eluent were optimized. The limits of detection and quantification of the developed MSPE HPLC method were 10.7 μg/L and 35.5 μg/L, respectively. The intra-day and inter-day repeatabilities were below 4.2% and 7.7%, respectively. The developed method was employed to determine trace levels of sulfadiazine in spiked water samples.

Preparation and performance study of a reactive polyurethane hot-melt adhesive/CS-Fe3O4 magnetic nanocomposite film/fabric.

Magnetic nanoparticles are attracting significant attention for their wide application as biomaterials and magnetic storage materials. As an environmentally friendly adhesive, reactive polyurethane hot-melt adhesive (PUR) is a biocompatible polymer with a wide range of applications. In this paper, chitosan (CS)-surface-modified magnetic Fe3O4 nanoparticles were synthesized by the sol–gel method. Surface modification of the Fe3O4 nanoparticles with CS enhanced their mechanical properties in PUR. The nanoparticles were characterized by Fourier transform infrared (FTIR) and X-ray diffraction (XRD) analyses, while their surface morphology was elucidated using scanning electron microscopy (SEM) and projection electron microscopy (TEM) techniques. Subsequently, PUR/CS–Fe3O4 magnetic nanocomposite films were prepared using an in situ method, wherein different amounts of CS–surface-modified magnetic Fe3O4 nanoparticles were doped into the PUR and coated on the films. The thermal, UV resistance and mechanical properties of the PUR/CS–Fe3O4 magnetic nanocomposite films were investigated by TGA, UV spectrometer and tensile testing. CS–Fe3O4 nanoparticles were successfully prepared using the sol–gel method and CS to modify the surface of the Fe3O4 nanoparticles. The results show that the mechanical properties and UV resistance of PUR/CS–Fe3O4 magnetic nanocomposites are improved by almost 50%, so the constructed PUR/CS–Fe3O4 magnetic nanocomposites have good UV-resistant properties and mechanical properties. The as-synthesized CS–Fe3O4 magnetic nanocomposites show great potential for application to mechanical and textile development.

Immobilization of lipase on β-cyclodextrin grafted and aminopropyl-functionalized chitosan/Fe3O4 magnetic nanocomposites: An innovative approach to fruity flavor esters esterification

The lipase from Bacillus licheniformis NCU CS-5 was immobilized onto β-cyclodextrin (CD) grafted and aminopropyl-functionalized chitosan-coated Fe3O4 magnetic nanocomposites (Fe3O4-CTS-APTES-GA-β-CD). Fourier transform infrared spectroscopy, thermogravimetry analysis, X-ray diffraction, scanning electron microscopy and transmission electron microscopy showed that not only the functionalized magnetic nanoparticles were synthesized but also the immobilized lipase was successfully produced. The immobilized lipase exhibited higher optimal pH value (10.5) and temperature (60℃) than the free lipase. The pH and thermal stabilities of the immobilized lipase were improved significantly compared to the free lipase. The immobilized lipase remained more than 80% of the relative activity at temperature of 60 ℃ and pH 12.0. The immobilized lipase also remained over 80% of its relative activity after 28 days of storage and 15 cycles of application. The application of the immobilized lipase in esterification of isoamyl acetate and pentyl valerate showed that maximum esterification efficiency was achieved in n-hexane having 68.0% and 89.2% respectively. Therefore, these results indicated that the Fe3O4-CTS-APTES-GA-β-CD nanoparticles are novel carriers for immobilizing enzyme, and the immobilized lipase can be used as an innovative green approach to the synthesis of fruity flavor esters in food industry.

Poly(catechol) modified Fe3O4 magnetic nanocomposites with continuous high Fenton activity for organic degradation at neutral pH.

Fe3O4 magnetic nanoparticles (MNPs) have been widely used as a recyclable catalyst in Fenton reaction for organic degradation. However, the pristine MNPs suffer from the drawbacks of iron leaching in acidic conditions as well as the decreasing catalytic activity of organic degradation at a pH higher than 3.0. To solve the problems, Fe3O4 MNPs were modified by poly(catechol) (Fe3O4/PCC MNPs) using a facile chemical co-precipitation method. The poly(catechol) modification improved both the dispersity and the surface negative charges of Fe3O4/PCC MNPs, which are beneficial to the catalytic activity of MNPs for organic degradation. Moreover, the poly(catechol) modification enhanced the efficiency of Fe(II) regeneration during Fenton reaction due to the acceleration of Fe(III) reduction by the phenolic/quinonoid redox pair. As a result, the Fenton reaction with Fe3O4/PCC MNPs could efficiently degrade organic molecules, exampled by methylene blue (MB), in an expanded pH range between 3.0 and 10.0. In addition, Fe3O4/PCC MNPs could be reused up to 8 cycles for the MB degradation with negligible iron leaching of lower than 1.5 mg L-1. This study demonstrated Fe3O4/PCC MNPs are a promising heterogeneous Fenton catalysts for organic degradation.

Synthesis of polypyrrole – chitosan magnetic nanocomposite for the removal of carbamazepine from wastewater: Adsorption isotherm and kinetic study

A polypyrrole–chitosan–Fe3O4 magnetic nanocomposite (PPy–CS–Fe3O4 MNC) was prepared by in situ coprecipitation of iron salts in the presence of chitosan followed by chemical oxidative polymerization of pyrrole on the magnetic chitosan. Afterward, the nanocomposite was applied as a magnetic nanosorbent for the removal of carbamazepine (CBZ) from the wastewater samples. The prepared adsorbent was characterized by various modern surface and microstructure analyzing methods. Several operating parameters affecting the removal efficiency of the CBZ including sample pH, amount of sorbent, initial concentration and adsorption time were investigated and adjusted. However, under the optimal conditions, the PPy–CS–Fe3O4 MNCs showed prominent removal performance compared to the bare Fe3O4 magnetic nanoparticles. According to the results, the PPy–CS–Fe3O4 MNCs could eliminate the CBZ from water medium with an efficiency of 94.5% in the 25 min. In contrast, it took about an hour to remove 65% of the CBZ using bare Fe3O4 magnetic nanoparticles. The experimental results revealed that the CBZ sorption on the PPy–CS–Fe3O4 MNCs was fitted well with the pseudo-second-order kinetic model (R2 = 0.9901). Moreover, the adsorption model was in accordance with the Langmuir isotherm with the adsorption capacity of 121.95 mg g−1. It was found that PPy–CS–Fe3O4 MNCs could be frequently applied for CBZ removal up to five times without noticeable decrease in its adsorption efficiency. The adsorption results established the high potential of synthesized MNCs as a robust and promising adsorbent for water treatment.

Hollow Polyaniline Microsphere/Fe3O4 Nanocomposite as an Effective Adsorbent for Removal of Arsenic from Water

Polyaniline hollow microsphere (PNHM)/Fe3O4 magnetic nanocomposites have been synthesized by a novel strategy and characterized. Subsequently, PNHM/Fe3O4-40 (Fe3O4 content: 40 wt.%) was used as an adsorbent for the removal of arsenic (As) from the contaminated water. Our investigations showed 98–99% removal of As(III) and As(V) in the presence of PNHM/Fe3O4-40 following pseudo-second-order kinetics (R2 > 0.97) and equilibrium isotherm data fitting well with Freundlich isotherm (R2 > 0.98). The maximum adsorption capacity of As(III) and As(V) correspond to 28.27 and 83.08 mg g−1, respectively. A probable adsorption mechanism based on X-ray photoelectron spectroscopy analysis was also proposed involving monodentate-mononuclear/bidentate-binuclear As-Fe complex formation via legend exchange. In contrast to NO3− and SO42− ions, the presence of PO43− and CO32− co-ions in contaminated water showed decrease in the adsorption capacity of As(III) due to the competitive adsorption. The regeneration and reusability studies of spent PNHM/Fe3O4-40 adsorbent showed ~83% of As(III) removal in the third adsorption cycle. PNHM/Fe3O4-40 was also found to be very effective in the removal of arsenic (<10 μg L−1) from naturally arsenic-contaminated groundwater sample.

Preparation of Magnetic g-C3N4/Fe3O4 Composite and Its Application in the Separation of Catechol from Water

Catechol has strong toxicity and deformity as well as carcinogenicity, and it is difficult to degrade naturally. Therefore, it is of great practical significance to develop efficient adsorbents to separate catechol from water quickly and effectively. In this work, g-C3N4/Fe3O4 magnetic nanocomposites were prepared using g-C3N4 as the matrix by chemical co-precipitation, mixing with Fe2+ and Fe3+ solutions. Then, g-C3N4/Fe3O4 was used, for the first time, as an adsorbent to investigate the removal rate of catechol under different conditions by the magnetic field separation method. The adsorption parameters of the g-C3N4/Fe3O4 nanocomposite were evaluated by the Langmuir and Freundlich adsorption models. The results showed that the g-C3N4/Fe3O4 nanocomposite presented a two-step adsorption behavior and a considerably high adsorption capacity. The removal rate of catechol reached 70% at the dosage of 50 mg, adsorption time of 30 min, and pH value of 6. Five adsorption–desorption cycles demonstrated that the g-C3N4/Fe3O4 material had good stability and reusability.

Efficient removal of methyl blue from aqueous solution by using poly(4-vinylpyridine)–graphene oxide–Fe3O4 magnetic nanocomposites

The poly(4-vinylpyridine)–graphene oxide–Fe3O4 magnetic nanohybrid (GO-Fe3O4@P4VP) was prepared and used as a novel nanoadsorbent to efficiently remove methyl blue (MB) from aqueous solution. The GO-Fe3O4@P4VP was characterized with scanning electron microscopy, transmission electron microscopy, elemental analysis, BET surface area, X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and vibrating sample magnetometer. The GO-Fe3O4@P4VP had high surface area, porous structure and magnetic properties. Adsorption performances of GO-Fe3O4@P4VP for MB were investigated at different pH, initial concentrations of MB, ionic strength, adsorbent dosage, contact time and the temperature. Adsorption equilibrium and kinetic process of MB on GO-Fe3O4@P4VP were well described by the Freundlich isotherm model and the pseudo-second-order kinetic model, respectively. Additionally, the characteristics of high adsorption capacity, rapid adsorption rate, good reusability and magnetic separation would make GO-Fe3O4@P4VP become a perfect candidate to remove MB in aqueous solution.

Photocatalytic oxidative desulfurization of liquid petroleum fuels using magnetic CuO–Fe3O4 nanocomposites

In the present study, dual-functional CuO–Fe3O4 magnetic nanocomposites (MNCs) have been prepared through a simple impregnation method and used as catalyst for photocatalytic oxidative desulfurization of model-fuel (dibenzothiophene, DBT in n-hexane) and real naphtha at moderate conditions. The CuO–Fe3O4 MNCs were characterized by X-ray diffraction, BET surface area and pore volume using nitrogen adsorption–desorption and VSM methods The effects of different reaction parameters such as initial DBT concentration in model-fuel, CuO–Fe3O4 MNCs dose, reaction time, H2O2/DBT molar ratio and CuO:Fe3O4 weight ratio of the MNCs were studied in detail. Results for model-fuel treatment showed that the prepared nanocomposite can eliminate 95.2% of DBT after 120 min under the following conditions: CuO:Fe3O4 weight ratio of 1:1, catalyst dose of 10 g/l, H2O2/DBT mole ratio of 7.5:1 and initial DBT concentration of 250 mg/l. Furthermore, 93% of sulfur conversion was obtained for naphtha fuel (initial sulfur concentration of 533 mg/l) after 240 min reaction time. The synthesized CuO–Fe3O4 magnetic nanocomposites combines the photocatalytic activity of CuO and the adsorption capacity of both Fe3O4 and CuO species, which make it have important applications in the deep desulfurization of liquid fuels.

Application of Fe3O4/RGO Nanocomposite as a Sorbent of Pesticides

In the present study, to extract the residue of seven pesticides (diazinon, chlorpyrifos, ethion, permethrine, cypermethrin, fenvalerate RR and fenvalerate SS) from raisin samples, reduced graphene oxide—Fe3O4 magnetic nanocomposite is applied as an adsorbent and then the preconcentrated pesticides were determined by GC–MS. The application of high adsorption capacity magnetic graphene oxide sheets in pesticides solid phase extraction, provides a fast and easy procedure without filtration or centrifugation. The extraction conditions were optimized by analyzing spiked raisin samples (80 ng mL−1). The parameters affecting the performance of the extraction such as nanoparticles concentration, extraction time, solution pH and desorption conditions were investigated using a univariate optimization process. The maximum adsorption was observed within 15 min at pH 7–8 using 0.4 mg mL−1 of adsorbent with the sample ionic strength of 0.02 M NaCl. Limits of detection and quantification were about 14 and 40 µg kg−1, respectively, for all of pesticides. The validated method was successfully applied for the determination of pesticides in raisin samples.

Synthesis and Characterization of Structure of Fe3O4@Graphene Oxide Nanocomposites

Nowadays, the hummers method for preparation of graphene oxide (GO) was improved. The grapheme oxide @ Fe3O4magnetic nanocomposites were synthesized by co-precipitation method. After analysing the morphology and structure of obtained nanocomposites by X-ray diffraction (XRD), transmission electron microscope (TEM) and Fourier transform infrared (FT-IR) spectroscopy, the result was shown as follows. The particle size of Fe3O4in nanocomposites is 30 nm. Many functional groups are found in grapheme oxide, and such groups could be used to bind with the drug. In the test for magnetic properties, the nanocomposites gathered rapidly in the vicinity of the permanent magnet. The nanocomposites, with high superparamagnetism, can be used in the following applications: drug targeting transports, drug carrier, and diagnosis assistant system.

Magnetic carbon nitride nanocomposites as enhanced peroxidase mimetics for use in colorimetric bioassays, and their application to the determination of H2O2 and glucose

Graphite-like carbon nitride − Fe3O4 magnetic nanocomposites were synthesized by a chemical co-precipitation method. The nanocomposites were characterized by transmission electron microscopy, X-ray diffraction, FTIR spectroscopy, X-ray photoelectron spectroscopy and magnetization hysteresis loops. The nanocomposites exhibit enhanced peroxidase-like activity (compared to that of graphite-like carbon nitride or Fe3O4 NPs). More specifically, they are capable of catalyzing the oxidation of different peroxidase substrates (such as TMB, ABTS or OPD) by H2O2 to produce the typical color reactions (blue, green or orange). The nanocomposites retain their magnetic properties and can be separated by an external magnet. On the basis of these findings, a highly sensitive and selective method was applied to the determination of H2O2 and glucose (by using glucose oxidase). It was successfully applied to the determination of glucose in (spiked) human serum. Compared to other nanomaterial-based peroxidase mimetics, the one described here provides distinctly higher sensitivity for both H2O2 and glucose, with detection limits as low as 0.3 μM and 0.25 μM, respectively.

Preparation of Au-polydopamine functionalized carbon encapsulated Fe₃O₄ magnetic nanocomposites and their application for ultrasensitive detection of carcino-embryonic antigen.

A novel carbon encapsulated Fe3O4 nanoparticles embedded in two-dimensional (2D) porous graphitic carbon nanocomposites (Fe3O4@C@PGC nanocomposites) were synthesized by situ synthesis strategy, which provided a sensor platform owing to a large aspect ratio and porous structure. Polydopamine (PDA) were modified on the surface of Fe3O4@C@PGC nanocomposites through self-polymerization of dopamine, acting as both the reductant and template for one-step synthesis of gold nanoparticles. The prepared Au/PDA/Fe3O4@C@PGC nanocomposites show ferromagnetic features, extremely excellent electron transfer, large specific surface area and excellent dispersing property. These are conducive to the electrochemical signal output and the immobilization of antibody. In this work, a highly label-free sensitive magnetic immunosensor was developed based on Au/PDA/Fe3O4@C@PGC nanocomposites for the detection of carcino-embryonic antigen (CEA). The magnetic glassy carbon electrode was used to fix the Au/PDA/Fe3O4@C@PGC nanocomposites with the help of magnetic force. Under the optimal conditions, the immunosensor exhibited a wide linear range (0.001 ng/mL–20.0 ng/mL), a low detection limit (0.33 pg/mL), good reproducibility, selectivity and acceptable stability. The proposed sensing strategy may provide a potential application in the detection of other cancer biomarkers.

Ternary P25–graphene–Fe3O4 nanocomposite as a magnetically recyclable hybrid for photodegradation of dyes

A ternary P25–graphene–Fe3O4 (PGF) magnetic nanocomposite has been successfully synthesized by decorating P25 and Fe3O4 nanoparticles on the reduced graphene oxide (RGO) through a facile solvothermal reaction and its ability to photodegrade organic dyes in aqueous solutions was investigated. The as-synthesized sample exhibits high photocatalytic activity toward various dyes and can be easily recycled by normal magnet due to the existence of Fe3O4 nanoparticles. Furthermore, owing to the presence of RGO, the photo-dissolution behavior of Fe3O4 nanoparticles occurring in the TiO2–Fe3O4 binary nanocomposites can be suppressed effectively, which increase the durability of such a recollectable photocatalyst. In addition, the PGF nanocomposite can work well under the acid pH conditions and also can photodegrade the mixtures of various dyes. These advantages make the PGF ternary composite an excellent photocatalyst use in practical wastewater treatment.

Synthesis, characterisation of polyaniline–Fe3O4 magnetic nanocomposite and its application for removal of an acid violet 19 dye

The present work deals with the development of a new method for the removal of dyes from an aqueous solution using polyaniline (PANI)–Fe3O4 magnetic nanocomposite. It is synthesised in situ through self-polymerisation of monomer aniline. Photocatalytic degradation studies were carried out for cationic acid violet 19 (acid fuchsine) dye using PANI–Fe3O4 nanocomposite in aqueous solution. Different parameters like catalyst dose, contact time and pH have been studied to optimise reaction condition. The optimum conditions for the removal of the dye are initial concentration 20 mg/l, adsorbent dose 6 gm/l, pH 7. The EDS technique gives elemental composition of synthesised PANI–Fe3O4. The SEM and XRD studies were carried for morphological feature characteristics of PANI–Fe3O4 nanocomposite. The VSM (vibrating sample magnetometer) gives magnetic property of PANI–Fe3O4 nanocomposite; also FT-IR analysis gives characteristics frequency of synthesised PANI–Fe3O4. Besides the above studies kinetic study has also been carried out.

Rapid removal of cadmium ions using green-synthesized Fe3O4 nanoparticles capped with diethyl-4-(4 amino-5-mercapto-4H-1,2,4-triazol-3-yl)phenyl phosphonate

Water-dispersible diethyl-4-(4-amino-5-mercapto-4H-1,2,4-triazol-3-yl)phenyl phosphonate (DEAMTPP)-capped biogenic Fe3O4 magnetic nanocomposite has been synthesized using Ananas comosus peel pulp extract for rapid removal of Cd(ii) ions from water.

Facile synthesis and characterization of polyethylenimine-coated Fe3O4 superparamagnetic nanoparticles for cancer cell separation

The detection of cancer cells in clinical samples is of great interest for a range of diagnostic applications, and separation and enrichment of cancer cells in low concentrations from complex sample matrices is necessary for efficient cancer diagnostics. In the present study, new surface-modified iron oxide nanoparticles were synthesized for the separation of lung cancer cells by simple precipitation of Fe(II) and Fe(III) salts in an aqueous ammonia solution, followed by the addition of polyethylenimine (PEI). The modified nanoparticles were characterized by X-ray diffractometry (XRD), transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and vibrating sample magnetometry (VSM). XRD and TEM revealed that the particles were ~10 nm in diameter, while FTIR and XPS showed that their surfaces were well coated with PEI. VSM results confirmed the superparamagnetic nature of PEI-coated Fe3O4 nanoparticles. The separation and enrichment of lung cancer cells from sputum samples was demonstrated using the synthesized developed PEI-coated Fe3O4 magnetic nanoparticles. Exfoliative cytopathology showed that the percentage of positive cells increased from 6.3% (38/600) in untreated sputum samples to 38.5% (231/600) in sputum samples treated with PEI-coated Fe3O4 magnetic nanocomposites. This finding indicated that PEI-coated Fe3O4 magnetic nanocomposites can be used to efficiently enrich lung cancer cells from sputum for subsequent cytopathological analysis.