Surface Plasmon Resonance Enhanced Faraday Rotation in Fe3O4/Ag Nanoparticles Doped Diamagnetic Glass

Diamagnetic TeO₂-PbO-B₂O₃ glasses were melt-quenching fabricated and characterized for Fe₃O₄/Ag nanoparticles doping through radio-frequency sputtering and thermal treatment techniques. The surface plasmon resonance influenced structure, composition, optical, and magneto optical properties of Fe₃O₄/Ag doped glasses were investigated through XRD, SEM, XPS analysis, and Faraday rotation measurement. The optimized sputtering and thermal conditions Fe₃O₄ and Ag nanoparticles were obtained. Under the optimized conditions, a great enhancement of Faraday rotation, thermal property, and big UV cutoff red-shift due to the excited surface plasma’s resonance effect was achieved in diamagnetic glass.

     

Novel and efficient method for immobilization and stabilization of β-d-galactosidase by covalent attachment onto magnetic Fe3O4–chitosan nanoparticles

A novel and efficient immobilization of β-d-galactosidase from Aspergillus oryzae has been developed by using magnetic Fe₃O₄–chitosan (Fe₃O₄–CS) nanoparticles as support. The magnetic Fe₃O₄–CS nanoparticles were prepared by electrostatic adsorption of chitosan onto the surface of Fe₃O₄ nanoparticles made through co-precipitation of Fe²⁺ and Fe³⁺. The resultant material was characterized by transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometry and thermogravimetric analysis. β-d-Galactosidase was covalently immobilized onto the nanocomposites using glutaraldehyde as activating agent. The immobilization process was optimized by examining immobilized time, cross-linking time, enzyme concentration, glutaraldehyde concentration, the initial pH values of glutaraldehyde and the enzyme solution. As a result, the immobilized enzyme presented a higher storage, pH and thermal stability than the soluble enzyme. Galactooligosaccharide was formed with lactose as substrate by using the immobilized enzyme as biocatalyst, and a maximum yield of 15.5% (w/v) was achieved when about 50% lactose was hydrolyzed. Hence, the magnetic Fe₃O₄–chitosan nanoparticles are proved to be an effective support for the immobilization of β-d-galactosidase.     

Covalent binding of α-chymotrypsin on the magnetic nanogels covered by amino groups

A new aminated carrier—magnetic nanogels covered by amino groups, was obtained by Hoffman degradation of polyacrylamide-coated Fe₃O₄ nanoparticles prepared by photochemical polymerization. α-Chymotrypsin (CT) was covalently bound to the magnetic nanogels by use of 1-ethyl-3-(3-dimethylaminepropyl) carbodiimide and N-hydroxysuccinimide at room temperature. Immobilization time, pH value of the reaction mixture and proportion of CT to the magnetic nanogels were investigated to obtain the optimum condition for CT immobilization. The maximal specific activity of the bound CT was determined to be 0.93 U/(mg min), 59.3% of free counterpart. The maximal binding capacity was measured to be 102 mg enzyme/g nanogel. Furthermore, the bound CT exhibited good thermal stability, storage stability and reusability.     

An electrochemical immunosensor for digoxin using core–shell gold coated magnetic nanoparticles as labels

A simple, sensitive, and low-cost immunosensor was designed for the detection of digoxin through core–shell gold coated magnetic nanoparticles (Fe₃O₄-Au-NPs) as an electrochemical label. Having had such a large potential for a variety of applications, Fe₃O₄-Au-NPs have attracted a considerable attention and are actively investigated recently. Digoxin is a cardiac glycoside which, at high level, can indicate an increased risk of toxicity. This new competitive electrochemical immunosensor was developed based on antigen–antibody reaction employing antigen (Ag) labeled Fe₃O₄-Au-NPs and PVA modified screen-printed carbon electrode surface in order to detect the serum digoxin. The structures of Fe₃O₄-Au-NPs were studied by transmission electron microscopy, X-ray diffraction and Fourier transformed infrared spectroscopy. Cyclic voltammetry and differential pulse voltammetry (DPV) were employed to determine the physicochemical and electrochemical properties of immunosensor. DPV was employed for quantitative detection of digoxin in biological samples. The developed immunosensor was capable to detect digoxin in the range from 0.5 to 5 ng mL^?1, with a detection limit as low as 0.05 ng mL^?1. The proposed method represented acceptable reproducibility, stability, and reliability for the rapid detection of digoxin in serum samples.     

Conjugation of α-chymotrypsin on a polymeric hydrophilic nanolayer covering magnetic nanoparticles

Magnetic nanoparticles, covered by a polymeric hydrophilic nanolayer containing reactive amino groups, were obtained via Hoffman degradation of the polyacrylamide-coated Fe₃O₄ nanoparticles synthesized by photochemical in situ polymerization, and then conjugated the model enzyme––α-chymotrypsin (CT) by use of EDC· HCl and NHS at room temperatures. The mechanism of photochemical in situ polymerization was briefly proposed in this paper. Superparamagnetic properties were retained for Fe₃O₄ after enzyme immobilization while slightly reducing the value of saturation magnetization. Crystalline structure of Fe₃O₄ after CT immobilization was consistent with that of the freshly prepared Fe₃O₄ by X-ray diffraction (XRD) analysis. The binding capacity was 69 and 61 mg enzyme/g nanogel determined by thermogravimetric (TG) analysis and by standard BCA protein assay, respectively. Specific activity of the immobilized CT was 0.93 U/(mg min), only 59.3% as that of free CT. Thermal stability of CT was improved after being bound to the amine-functionalized magnetic nanogel.     

Biodesulfurization of Dibenzothiophene by Microbial Cells Coated with Magnetite Nanoparticles

Microbial cells of Pseudomonas delafieldii were coated with magnetic Fe₃O₄ nanoparticles and then immobilized by external application of a magnetic field. Magnetic Fe₃O₄ nanoparticles were synthesized by a coprecipitation method followed by modification with ammonium oleate. The surface-modified Fe₃O₄ nanoparticles were monodispersed in an aqueous solution and did not precipitate in over 18 months. Using transmission electron microscopy (TEM), the average size of the magnetic particles was found to be in the range from 10 to 15 nm. TEM cross section analysis of the cells showed further that the Fe₃O₄ nanoparticles were for the most part strongly absorbed by the surfaces of the cells and coated the cells. The coated cells had distinct superparamagnetic properties. The magnetization (δ_s) was 8.39 emu · g⁻¹. The coated cells not only had the same desulfurizing activity as free cells but could also be reused more than five times. Compared to cells immobilized on Celite, the cells coated with Fe₃O₄ nanoparticles had greater desulfurizing activity and operational stability.     

Iron Oxide Nanoparticles Affects Behaviour and Monoamine Levels in Mice

Iron oxide (Fe₂O₃) nanoparticles (NPs) attract the attention of clinicians for its unique magnetic and paramagnetic properties, which are exclusively used in neurodiagnostics and therapeutics among the other biomedical applications. Despite numerous research findings has already proved neurotoxicity of Fe₂O₃-NPs, factors affecting neurobehaviour has not been elucidated. In this study, mice were exposed to Fe₂O₃-NPs (25 and 50 mg/kg body weight) by oral intubation daily for 30 days. It was observed that Fe₂O₃-NPs remarkably impair motor coordination and memory. In the treated brain regions, mitochondrial damage, depleted energy level and decreased ATPase (Mg²⁺, Ca²⁺ and Na⁺/K⁺) activities were observed. Disturbed ion homeostasis and axonal demyelination in the treated brain regions contributes to poor motor coordination. Increased intracellular calcium ([Ca²⁺]_i) and decreased expression of growth associated protein 43 (GAP43) impairs vesicular exocytosis could result in insufficient signal between neurons. In addition, levels of dopamine (DA), norepinephrine (NE) and epinephrine (EP) were found to be altered in the subjected brain regions in correspondence to the expression of monoamine oxidases (MAO). Along with all these factors, over expression of glial fibrillary acidic protein (GFAP) confirms the neuronal damage, suggesting the evidences for behavioural changes.

     

In vitro cytotoxicity screening of water-dispersible metal oxide nanoparticles in human cell lines

In this study, we present in vitro cytotoxicity of iron oxide (Fe₃O₄) and manganese oxide (MnO) using live/dead cell assay, lactate dehydrogenase assay, and reactive oxygen species detection with variation of the concentration of nanoparticles (5–500 μg/ml), incubation time (18–96 h), and different human cell lines (lung adenocarcinoma, breast cancer cells, and glioblastoma cells). The surface of nanoparticles is modified with polyethyleneglycol-derivatized phospholipid to enhance the biocompatibility, water-solubility, and stability under an aqueous media. While the cytotoxic effect was negligible for 18 h incubation even at highest concentration of 500 μg/ml, MnO nanoparticle represented higher level of toxicity than those of Fe₃O₄ and the commercial medical contrast reagent, Feridex after 2 and 4 day incubation time. However, the cytotoxicity of Fe₃O₄ is equivalent or better than Feridex based on the live/dead cell viability assay. The engineered MnO and Fe₃O₄ exhibited excellent stability compared with Feridex for a prolonged incubation time.     

In vitro spectroscopic investigation of groove binding interaction of Fe3O4@CaAl-LDH@L-Dopa with calf thymus DNA

Abstract

The principal goal of this study is to evaluate the interaction of Fe₃O₄@CaAl-LDH@L-Dopa and Fe₃O₄@CaAl-LDH nanoparticles with calf thymus DNA. The magnetic nanoparticles were previously prepared by a chemical co-precipitation method, and the surface of the Fe₃O₄ nanoparticles was coated with CaAl layered double hydroxides. The antiparkinsonian drug “L-Dopa” was carried by this core–shell nanostructure to achieve the drug delivery system with suitable properties for biological applications. Also, the interaction of Fe₃O₄@CaAl-LDH@L-Dopa and Fe₃O₄@CaAl-LDH nanoparticles with CT-DNA was studied using, UV–Visible spectroscopy, viscosity, circular dichroism (CD), and fluorescence spectroscopy techniques. The results of investigations demonstrated that Fe₃O₄@CaAl-LDH@L-Dopa and Fe₃O₄@CaAl-LDH nanoparticles have interacted via minor groove binding and intercalated to CT-DNA, respectively.     

Nanostructured materials for magnetic biosensing

BackgroundMagnetic nanoparticles (MNPs) are at the leading edge of the field of biomedical applications and magnetic biosensing.MethodsMNPs were fabricated by electrophysical methods of the laser target evaporation (LTE) and spark discharge with electrodynamic acceleration of plasma jumpers (SD). Synthesis of polyacrylamide hydrogel was done in the presence of Fe₂O₃ MNPs in different concentrations obtained by LTE. [FeNi/Ti]₃/Cu/[Ti/FeNi]₃/Ti multilayers for giant magnetoimpedance (GMI) based sensitive elements were prepared by rf-sputtering for testing a biosensor prototype.ResultsIron oxide MNPs, ferrofluids, ferrofluids contacting with biological systems, synthetic ferrogels mimicking natural tissues – are the steps of the discussed in this work development of bionanomaterials. Thorough the structural and magnetic studies of a multilayered sensitive element, MNPs and ferrogels insure the complete characterization of biosensor prototype. The GMI responses were carefully evaluated in initial state and in the presence of ferrogel with known concentration of MNPs. SD MNPs had the smallest 5–8 nm size. This nanomaterial was characterized by large internal strains of the order of 25 × 10^− 3, which can play an important role for the interaction with different biosystems.ConclusionsIron oxide MNPs were fabricated by LTE and SD methods. SD MNPs had the smallest 5–8 nm size and large internal strains of the order of 25 × 10^− 3. Designed GMI biosensor prototype allowed precise evaluation of the stray field of the MNPs present in the ferrogel by evaluating the systematic changes of the GMI in a 20–400 MHz frequency range.General significanceThis work summarizes recent developments in the field of nanomaterials potentially applicable in magnetic biosensing.     

An organic–inorganic hybrid nanostructure-functionalized electrode for electrochemical immunoassay of biomarker by using magnetic bionanolabels

A new electrochemical immunoassay of alpha-fetoprotein (AFP) was developed on an organic–inorganic hybrid nanostructure-functionalized carbon electrode by coupling with magnetic bionanolabels. Multi-walled carbon nanotubes (CNTs), single-stranded DNA, thionine and AFP were utilized for the construction of the immunosensor, while the core–shell Fe₃O₄-silver nanocomposites were employed for the label of horseradish peroxidase-anti-AFP conjugates (HRP-anti-AFP-AgFe). Electrochemical measurement toward AFP was carried out by using magnetic bionanolabels as traces and H₂O₂ as enzyme substrate with a competitive-type immunoassay mode. Experimental results indicated that the immunosensors with carbon nanotubes and DNA exhibited better electrochemical responses than those of without carbon nanotubes or DNA. Under optimal conditions, the electrochemical immunosensor by using HRP-anti-AFP-AgFe as signal antibodies exhibited a linear range of 0.001–200 ng mL⁻¹ AFP with a low detection limit of 0.5 pg mL⁻¹ at 3s_B. Both intra- and inter-assay coefficients of variation were 7.3%, 9.4%, 8.7% and 10.2%, 7.8%, 9.4% toward 0.01, 30, 120 ng mL⁻¹ AFP, respectively. The specificity and stability of the electrochemical immunoassay were acceptable. In addition, the methodology was validated for 12 clinical serum specimens including 9 positive specimens and 3 normal specimens, receiving a good correlation with the results obtained from the referenced electrochemiluminescence assay.     

Microbial community analysis of simultaneous ammonium removal and Fe3+ reduction at different influent ammonium concentrations

This study investigates the impacts of influent ammonium concentrations on the microbial community in immobilized heterotrophic ammonium removal system. Klebsiella sp. FC61, the immobilized species, has the ability to perform simultaneous ammonium removal and Fe³⁺ reduction. It was found that average ammonium removal rate decreased from 0.308 to 0.157 mg/L/h, as the influent NH₄ ⁺-N was reduced from 20 to 10 mg/L. Meanwhile, at a total Fe³⁺ concentration of 20 mg/L, the average Fe³⁺ reduction removal efficiency and rate decreased from 44.61% and 0.18 mg/L/h, to 27.10% and 0.11 mg/L/h, respectively. High-throughput sequencing was used to observe microbial communities in bioreactor Samples B1, B2, and B3, after exposure to different influent NH₄ ⁺-N conditions. Results show that higher influent NH₄ ⁺-N concentrations increased microbial richness and diversity and that Klebsiella sp. FC61 play a functional role in the simultaneous removal of NH₄ ⁺-N and Fe³⁺ reduction in bioreactor systems.

     

Surface Plasmon Resonance and Enhanced Fluorescence Application of Single-step Synthesized Elliptical Nano Gold-embedded Antimony Glass Dichroic Nanocomposites

A novel series of elliptical gold (Au⁰) nanoparticles (18–40 nm) embedded antimony glass (K₂O-B₂O₃-Sb₂O₃) dichroic nanocomposites have been synthesized by a single-step melt-quench in-situ thermochemical reduction technique. X-ray and selected area electron diffractions manifest growth of Au⁰ nanoparticles along the (111) and (200) crystallographic planes. The transmission electron microscopic image reveals elliptical Au⁰ nanoparticles having an aspect ratio varying in the range 1.2–2.1. The dichroic behavior of the nanocomposites arises due to elliptical shape of the Au⁰ nanoparticles. These nanocomposites show strong surface plasmon resonance (SPR) band of Au nanoparticles in the range 610–681 nm and it exhibit red-shifts with increasing Au concentration. They, when co-doped with Sm₂O₃ and excited at 949 nm, exhibit about sevenfold enhancement of the upconverted red emission transition of ⁴G_5/2→⁶H_9/2 at 636 nm due to local electric field enhancement effect of Au⁰ nanoparticles induced by its SPR. These nanocomposites are the promising materials for laser, display, and various nanophotonic applications.     

In situ preparation of magnetic Fe3O4-chitosan nanoparticles for lipase immobilization by cross-linking and oxidation in aqueous solution

A new and simple method has been proposed to prepare magnetic Fe₃O₄-chitosan (CS) nanoparticles by cross-linking with sodium tripolyphosphate (TPP), precipitation with NaOH and oxidation with O₂ in hydrochloric acid aqueous phase containing CS and Fe(OH)₂, and these magnetic CS nanoparticles were used to immobilize lipase. The effects on the sequence of adding NaOH and TPP, the reaction temperature, and the ratio of CS/Fe(OH)₂ were studied. TEM showed that the diameter of composite nanoparticles was about 80 nm, and that the magnetic Fe₃O₄ nanoparticles with a diameter of 20 nm were evenly dispersed in the CS materials. Magnetic measurement revealed that the saturated magnetisation of the Fe₃O₄-CS nanoparticles could reach 35.54 emu/g. The adsorption capacity of lipase onto nanoparticles could reach 129 mg/g; and the maximal enzyme activity was 20.02 μmol min⁻¹ mg⁻¹ (protein), and activity retention was as high as 55.6% at a certain loading amount.     

NiCo2O4 Nanofibers as Carbon‐Free Sulfur Immobilizer to Fabricate Sulfur‐Based Composite with High Volumetric Capacity for Lithium–Sulfur Battery

Both the energy density and cycle stability are still challenges for lithium–sulfur (Li–S) batteries in future practical applications. Usually, light‐weight and nonpolar carbon materials are used as the hosts of sulfur, however they struggle on the cycle stability and undermine the volumetric energy density of Li–S batteries. Here, heavy NiCo₂O₄ nanofibers as carbon‐free sulfur immobilizers are introduced to fabricate sulfur‐based composites. NiCo₂O₄ can accelerate the catalytic conversion kinetics of soluble intermediate polysulfides by strong chemical interaction, leading to a good cycle stability of sulfur cathodes. Specifically, the S/NiCo₂O₄ composite presents a high gravimetric capacity of 1125 mAh g^?1 at 0.1 C rate with the composite as active material, and a low fading rate of 0.039% per cycle over 1500 cycles at 1 C rate. In particular, the S/NiCo₂O₄ composite with the high tap density of 1.66 g cm^?3 delivers large volumetric capacity of 1867 mAh cm^?3, almost twice that of the conventional S/carbon composites.     

SPR Label-Free Biosensor with Oxide-Metal-Oxide-Coated D-Typed Optical Fiber: a Theoretical Study

In this article, a surface plasmon resonance (SPR) biosensor based on D-typed optical fiber coated by Al₂O₃/Ag/Al₂O₃ film is investigated numerically. Resonance in near infrared with an optimized architecture is achieved. Refractive index sensitivity of 6558 nm/RIU (refractive index unit) and detection limit of 1.5 × 10⁻⁶ RIU, corresponding to 0.4357 nm/μM and detection limit of 23 nM in BSA (bovine serum albumin) concentration sensing, are obtained. The analysis of the performance of the sensor in gaseous sensing indicates that this proposed SPR sensor is much suitable for label-free biosensing in aqueous media.

     

Preparation and characterization of magnetic gold nanoparticles to be used as doxorubicin nanocarriers

Magnetic targeted drug delivery (MTD), using magnetic gold nanoparticles (Fe₃O₄@Au NPs) conjugated with an anti-cancer drug is a promise modality for cancer treatment. In this study, Fe₃O₄@Au NPs were prepared and functionalized with thiol-terminated polyethylene glycol (PEG), then loaded with anti-cancer drug doxorubicin (DOX). The physical properties of the prepared NPs were characterized using different techniques. Transmission electron microscopy (TEM) revealed the mono dispersed nature of Fe₃O₄@Au NPs with an average size of 20 nm which was confirmed using Dynamic light scattering (DLS) measurements. Zeta potential measurements along with UV–VIS spectroscopy demonstrated surface DOX loading on Fe₃O₄@Au NPs. Energy Dispersive X-ray Spectroscopy (EDX) assured the existence of both iron and gold elements in the prepared NPs. The paramagnetic properties of the prepared NPs were assessed by vibrating sample magnetometer (VSM). The maximum DOX-loading capacity was 100 μg DOX/mg of Fe₃O₄@Au NPs. It was found that DOX released more readily at acidic pH. In vitro studies on MCF-7 cell line elucidated that DOX loaded Fe₃O₄@Au NPs (Fe₃O₄@Au-PEG-DOX) have more potent therapeutic effect than free DOX. Knowledge gained in this study may open the door to pursue Fe₃O₄@Au NPs as a viable nanocarriers for different molecules delivery in many diagnostic and therapeutic applications.     

Evaluation of the Biodistribution of Magnetoliposomes in a Tumor and Organs of Mice by Electron Paramagnetic Resonance Spectroscopy

Electron paramagnetic resonance spectroscopy has been applied for the first time to study the bio-distribution of magnetoliposomes formed with magnetite nanoparticles (Fe₃O₄) in tumors and organs of Lewis carcinoma-bearing mice in the absence and presence of an external magnetic field. The animals of the experimental group were subjected to an external magnetic field (0.6 T) in the tumor area after intravenous injection of magnetoliposomes at a dose of 7.56 Fe/kg. Analysis of the electron-spin resonance spectra of mouse organs and tissue samples showed that exposure to a magnetic field resulted in a two-fold increase in Fe₃O₄ accumulation within the tumor (p < 0.05) compared to the control; this makes it possible to recommend the obtained magnetoliposomes for use as a magnetically controlled carriers for targeted delivery of antitumor agents. A high concentration of superparamagnetic magnetite nanoparticles was detected in the liver in the absence and presence of an external magnetic field. The differences in the accumulation of Fe₃O₄ in the lungs and liver in the presence of a magnetic field were statistically insignificant.

     

Single-Step Synthesis and Surface Plasmons of Bismuth-Coated Spherical to Hexagonal Silver Nanoparticles in Dichroic Ag:Bismuth Glass Nanocomposites

Here, we report for the first time the synthesis of bismuth-coated silver nanoparticles in dichroic bismuth glass nanocomposites by a novel and simple one-step melt quench technique without using any external reducing agent. The metallic silver nanoparticles (Ag NPs) were generated first, and subsequently, metallic bismuth was deposited on the Ag NPs and formed a thick layer. The reduction of Bi³⁺ to Bi^o and subsequently its deposition on the Ag NPs (which were formed earlier than Bi^o) in the K₂O–Bi₂O₃–B₂O₃ (KBB) glass system have been explained by their standard reduction potentials. The UV–vis absorption spectra show a prominent surface plasmon resonance (SPR) absorption band at 575 nm at lower concentrations (up to 0.01 wt%); three bands at 569, 624 and 780 nm at medium concentration (0.02–0.03 wt%); and two weak bands at 619 and 817 nm at highest concentration (0.06 wt%) of silver. They have been explained by the electrodynamics theories. TEM images reveal the conversion of spheroidal (5–15 nm) to hexagonal (10–35 nm) shaped Ag NPs with the increase in concentration of silver (up to 0.06 wt%). SAED pattern confirms the crystalline planes of rhombohedral bismuth and cubic silver. Thermal treatment at 360 °C, which is the glass transformation temperature (T _g) of the sample containing lower concentration of silver (0.007 wt%), shows red-shifted SPR band due to increase in size of NPs. Whereas the sample containing higher concentration (0.06 wt%) of silver under similar treatment exhibited changes in SPR spectral profile happened due to conversion to spherical NPs from hexagonal shape and reduction in size (10–20 nm) of NPs after heat treatment for 65 h. HRTEM images corroborate the different orientations of the NPs. FESEM images reveal hexagonal disk like structure having different orientations. Dichroic nature of the nanocomposites has been explained with the size and shape of Ag nanoparticles. We believe that this work will create new avenues in the area of nanometal–glass hybrid nanocomposites and the materials have significant applications in the field of optoelectronics and nanophotonics.     

DNA binding and cytotoxicity studies of magnetic nanofluid containing antiviral drug oseltamivir

In this work, the possibility of preparing a nanoparticle with improved treatment properties was investigated. In this regard, synthesis, characterization, in vitro cytotoxicity and DNA binding of Fe₃O₄@oleate/oseltamivir magnetic nanoparticles (MNPs) were investigated. Fe₃O₄ nanoparticles were synthesized via chemical co-precipitation and coated by oleate bilayers. Then, Fe₃O₄@OA MNPs were functionalized with an antiviral drug (oseltamivir), for better biological applications. The MNPs were subsequently characterized by zeta sizer and Zeta potential measurements, Fourier transform infrared (FT-IR) spectroscopy, vibrating sample magnetometer (VSM) and transmission electron microscopy (TEM) analyses. The TEM image demonstrated that average sizes of Fe₃O₄@OA/oseltamivir MNPs were about 8?nm. The in vitro cytotoxicity of Fe₃O₄@OA/oseltamivir MNPs was studied against cancer cell lines (MCF-7 and MDA-MB-231) and compared with oseltamivir drug. The results illustrated that Fe₃O₄@OA/oseltamivir magnetic nanoparticles have better antiproliferative effects on the mentioned cell lines as compared with oseltamivir. Also, in vitro DNA binding studies were done by UV–Vis, circular dichroism, and Fluorescence spectroscopy. The results indicated that Fe₃O₄@OA/oseltamivir MNPs bound to DNA via groove binding. Moreover, this magnetic nanofluid has potential for magnetic hyperthermia therapy due to magnetic core of its nanoparticles.

Communicated by Ramaswamy H. Sarma