Acid-functionalized Fe3O4 Nanoparticles Research Articles

Synthesis of magnetically tuneable molybdic acid-functionalized Fe3O4 nanoparticles for efficient dye removal in aqueous media

Synthesis of magnetically tuneable molybdic acid-functionalized Fe3O4 nanoparticles for efficient dye removal in aqueous media

Design and Application of Microfluidic Capture Device for Physical-Magnetic Isolation of MCF-7 Circulating Tumor Cells.

Circulating tumor cells (CTCs) are a type of cancer cell that spreads from the main tumor to the bloodstream, and they are often the most important among the various entities that can be isolated from the blood. For the diagnosis of cancer, conventional biopsies are often invasive and unreliable, whereas a liquid biopsy, which isolates the affected item from blood or lymph fluid, is a less invasive and effective diagnostic technique. Microfluidic technologies offer a suitable channel for conducting liquid biopsies, and this technology is utilized to extract CTCs in a microfluidic chip by physical and bio-affinity-based techniques. This effort uses functionalized magnetic nanoparticles (MNPs) in a unique microfluidic chip to collect CTCs using a hybrid (physical and bio-affinity-based/guided magnetic) capturing approach with a high capture rate. Accordingly, folic acid-functionalized Fe3O4 nanoparticles have been used to capture MCF-7 (breast cancer) CTCs with capture efficiencies reaching up to 95% at a 10 µL/min flow rate. Moreover, studies have been conducted to support this claim, including simulation and biomimetic investigations.

Preparation and characterization of sulfamic acid-functionalized Fe3O4 nanoparticles as an efficient magnetic nanocatalyst for the facile and eco-friendly synthesis of quinoxalines, benzothiazoles, and benzoxazoles

Preparation and characterization of sulfamic acid-functionalized Fe3O4 nanoparticles as an efficient magnetic nanocatalyst for the facile and eco-friendly synthesis of quinoxalines, benzothiazoles, and benzoxazoles

Preparation and characterization of a magnetic catalyst for coupling reactions

Pd supported on 2-aminoquinoline-7-carboxylic acid functionalized Fe3O4 nanoparticles (Fe3O4-AQCA-Pd) as a new magnetic nanocatalyst was prepared and characterized by ICP-AES, FT-IR, XRD, SEM, TEM, TGA, XRD and EDX techniques. This nanocatalyst is employed for coupling reactions of pyridyl esters with phenylboronic acid to obtain ketone derivatives in good to excellent yields. This green catalyst was easily removed, reused several times with no significant loss of activity and provided a clean synthesis with excellent yield in reduced times.

A nano-organo catalyst mediated approach towards the green synthesis of 3-methyl-4-(phenyl)methylene-isoxazole-5(4H)-one derivatives and biological evaluation of the derivatives as a potent anti-fungal and anti-tubercular agent

An efficient and green protocol for the one-pot synthesis of 3-methyl-4-(phenyl)methylene-isoxazole-5(4H)-one derivatives catalyzed by a novel acid functionalized Fe3O4 nanoparticles (NPs) is reported herein. The catalyst was synthesized and characterized by various analytical techniques. Ultrasound energy has been efficiently exploited for the preparation of the catalyst as well as the synthesis of a series of the aforesaid compounds. The salient features of this protocol include mild reaction condition, easy catalyst recovery, shorter reaction time and use of environmental-friendly solvents. In addition, preliminary in-vitro antifungal and antimycobacterial screening of the synthesized compounds were conducted against three pathogenic fungi viz., Aspergillus fumigatus, Aspergillus flavus, Fusarium oxysporum and M. tuberculosis H37Rv respectively. Interestingly, 3-chloromethyl-4-(phenyl) methylene-isoxazole-5(4H)-one series exhibited over 50% growth inhibition against the mycelial growth of the fungi Fusarium oxysporum at 100 μg/mL. Whereas 4-(1H-indol-3-ylmethylene)-3-methyl-4H-isoxazol-5-one and 3-chloromethyl-4-(2,4,6-trimethyl-benzylidene)-4H-isoxazol-5-one displayed antimycobacterial activity against Mycobacterium tuberculosis H37Rv strain equipotent to the standard drug, ethambutol (MIC 1.56 μg/mL).

Synthesis of Pd supported on 3,4-diaminobenzoic acid functionalized Fe3O4 nanoparticles as a magnetic catalyst for synthesis of 2-methoxy-2-phenylacetonitrile derivative via a strecker-type reaction under ambient and solvent-free conditions

Pd supported on 3,4-diaminobenzoic acid functionalized Fe3O4 magnetic nanoparticles as an organic-inorganic hybrid heterogeneous catalyst was fabricated and characterized by FT-IR, XRD, SEM, TEM, TGA, VSM, EDX, and ICP-AES techniques. The catalytic activity of the magnetic catalyst was probed through a Strecker-type reaction for one-pot synthesis of 2-methoxy-2-phenylacetonitrile derivatives under ambient and solvent-free conditions. Simple procedure, high yields, short reaction time, and environmentally benign method are advantages of this protocol. The catalyst was readily separated using an external magnet and reusable without significant loss of its catalytic efficiency.

Preparation of a novel, efficient, and recyclable magnetic catalyst, Cu(II)-OHPC-Fe3O4 nanoparticles, and a solvent-free protocol for the synthesis of coumarin derivatives

Cu(II) supported on 5-oxo-4,5-dihydro-pyrrole-3-carboxylic acid functionalized Fe3O4 nanoparticles (Cu(II)-OHPC-Fe3O4) as a new magnetic nanocatalyst was prepared and characterized by ICP-AES, FT-IR, XRD, SEM, TEM, TGA, XRD, VSM and EDX techniques. Prepared nanocatalyst (Cu(II)-OHPC-Fe3O4) is employed for Pechmann reactions between different substituted phenols and ethyl acetoacetate to obtain new products of coumarin derivatives in good to excellent yields. This green catalyst was easily removed, reused several times with no significant loss of its activity and provided clean synthesis with excellent yield and reduced time.

Thermosensitive Core-Shell Fe3O4@poly(N-isopropylacrylamide) Nanogels for Enhanced Oil Recovery.

An investigation on the application of thermosensitive core-shell Fe3O4@PNIPAM nanogels in enhanced oil recovery was successfully performed. Here, the unique core-shell architecture was fabricated by conducting the polymerization at the surface of 3-butenoic acid-functionalized Fe3O4 nanoparticles and characterized using X-ray diffraction (XRD), 1H NMR, vibration sample magnetometer (VSM), and high-resolution transmission electron microscopy (HR-TEM). According to the results, this core-shell structure was beneficial for achieving the desired high viscosity and low nanofluid mobility ratio at high temperatures, which is essential for enhanced oil recovery (EOR) application. The results demonstrated that the nanogels exhibited a unique temperature-dependent flow behavior due to the PNIPAM shell's ability to transform from a hydrated to a dehydrated state above its low critical solution temperature (LCST). At such conditions, the nanogels exhibited a significantly low mobility ratio (M = 0.86), resulting in an even displacement front during EOR and leads to higher oil production. Based on the result obtained from sand pack flooding, about 25.75% of an additional secondary oil recovery could be produced when the nanofluid was injected at a temperature of 45 °C. However, a further increase in the flooding temperature could result in a slight reduction in oil recovery due to the precipitation of some of the severely aggregated nanogels at high temperatures.

Preparation and Characterization of a Novel Magnetic Nano Catalyst for Synthesis and Antibacterial Activities of Novel Furan-2(5H)-Ones Derivatives

Sulfamic acid 2-Aminobenzothiazole-6-carboxylic acid functionalized Fe3O4 nanoparticles as a novel organic-inorganic hybrid heterogeneous catalyst were manufactured and characterized by FT-IR, XRD, TGA, SEM, TEM, and VSM techniques. The catalytic activity of the magnetic catalyst was investigated through the one-pot synthesis of novel 3,4,5-trisubstituted furan-2(5H)-ones derivatives from aryl aldehydes, 4-amino pyridine, and dimethyl acetylenedicarboxylate. The structure of all the new synthesized derivatives was determined by FT-IR, 1H-NMR, and 13C-NMR. The synthetic compounds exert moderate activity against both Gram-positive and Gram-negative bacteria and their effectiveness is higher against Bacillus subtilis. This green nano catalytic procedure has good reversibility and provides clean production in a short reaction time. These characters make the method practical and economical for researchers.

Synthesis of amino acid functionalized Fe3O4 nanoparticles for adsorptive removal of Rhodamine B

L-Aspartic acid (L-Asp) functionalized magnetite nanoparticles (Fe3O4 NPs) were synthesized through a facile co-precipitation method using L-Asp as a capping agent. UV–Vis, FTIR, XRD, SEM, EDS, TEM, and VSM techniques were used to investigate the formation, morphology, elemental composition, and magnetic properties of the synthesized Fe3O4 NPs. Highly crystalline and spherical shaped pure phase Fe3O4 NPs were successfully synthesized using amino acid as a capping agent. The magnetic measurement analysis confirms the superparamagnetic nature of the synthesized L-Asp capped Fe3O4 NPs. The adsorption efficiency of L-Asp capped Fe3O4 NPs was assessed by the removal of Rhodamine B (RhB). The optimum removal efficiency was found to be 7.7 mg g−1 using 1 mg mL−1 adsorbent, and 30 mg L−1 RhB at pH 7 and 25 °C. The regression (R2adj) and standard deviation (SD) analysis were used to validate both kinetic and isotherm models. Avrami fractional-order and Liu models were selected as the best kinetic and isotherms, respectively. The maximum adsorption capacity (Qo) of L-Asp Fe3O4 NPs toward RhB Liu’s model was found to be 10.44 mg g−1.

Synthesis and characterization of a novel Pyrrole-2-carboxylic acid functionalized magnetic Fe3O4 as a nanocatalyst for synthesis and antibacterial activities of novel isoxazolo[4,3-e]indazole derivatives

Pyrrole-2-carboxylic acid functionalized Fe3O4 nanoparticles as a novel organic–inorganic hybrid heterogeneous catalyst was manufactured and characterized by X-ray diffraction (XRD) analysis, Fourier transform infrared (FT-IR), Transmission Electron Microscopy (TEM), Thermogravimetric analysis (TGA), Scanning electron microscope (SEM), Vibrating sample magnetometer (VSM) techniques. The catalytic activity of the nanomagnetic catalyst was investigated in the new heterocyclic system isoxazolo[4,3-e]indazole was synthesized via the nucleophilic substitution of a hydrogen in 5-nitro-1-p-tolyl-1H-indazole with different 2-phenylacetonitrile derivatives in basic medium. The synthetic compounds exert moderate activity against both Gram positive and Gram negative bacteria and their effectiveness is higher against Bacillus subtilis. This green magnetic nanocatalytic procedure has a good reversibility and provides clean production in a short reaction time.

Two-dimensional superlattice-like sheets of superparamagnetic graphene oxide/magnetic nanoparticle hybrids

Using a simple and facile method, we precisely controlled the two-dimensional layered array structure of graphene oxide (GO)–iron oxide (Fe3O4) nanoparticle hybrid multilayer films and investigated the correlation between the assembled structure of the hybrid films and their magnetic properties. GO–Fe3O4 nanoparticle hybrids were obtained via the ligand exchange of oleic acid-functionalized Fe3O4 nanoparticles with GO at the gas–liquid interface. Hybrids of oriented Fe3O4 nanoparticles and GO monolayers spontaneously formed at the gas–liquid interface, which were subsequently deposited on solid substrates using the Langmuir–Schaefer (LS) technique. Two-dimensional superlattices of GO–Fe3O4 nanoparticle hybrids were fabricated through repeated LS deposition of the nanoparticle monolayer with a hexagonal array structure sandwiched between GO monolayers. The magnetic properties of the GO–Fe3O4 multilayer were measured using SQUID magnetometry. From the field cooling/zero field cooling results, we found that the 2D superlattice-like layered structure of the GO–Fe3O4 multilayer facilitates the layer-dependent properties in the out-of-plane field case due to the dipolar interactions between the top and bottom layers.

Preparation and characterization of isatin complexed with Cu supported on 4-(aminomethyl) benzoic acid-functionalized Fe3O4 nanoparticles as a novel magnetic catalyst for the Ullmann coupling reaction

Isatin complexed with Cu supported on 4-(aminomethyl) benzoic acid-functionalized Fe3O4 nanoparticles (Cu-IS-AMBA-MNPs) as a new catalyst was designed, prepared and characterized by appropriate analyses. The heterogeneous reusable catalyst was successfully used for the efficient and widespread syntheses of diaryl ethers and diarylamines via the Ullmann coupling reaction. This green catalyst was easily removed, reused several times with no significant loss of its activity, and provided a clean synthesis with excellent yield and reduced time.

Phytic acid functionalized Fe3O4 nanoparticles loaded with Ti(IV) ions for phosphopeptide enrichment in mass spectrometric analysis.

A novel magnetic nanomaterial for use in metal ion based affinity chromatography is described. It is based on the chelation between the phosphate groups of phytic acid (PA) and Ti(IV) ions. Due to the large number (6) of phosphate groups of PA, it has a large capacity for Ti(IV) ions. PA was first immobilized on magnetite nanoparticles (PA-MNPs) and then loaded with Ti(IV) ions to obtain the sorbent (Ti-PA-MNPs). The fraction of Ti(IV) ions on the surface of PA-MNPs that is exposed to the solution binds the phosphate groups of phosphopeptides. The bound phosphopeptides can then be magnetically separated. The method was applied to the enrichment of the phosphopeptides in a β-casein tryptic digest. A tryptic digest of bovine serum albumin (BSA) was added at a molar ratio (β-casein to BSA) of 1:2000 to study selectivity. The phosphopeptides were quantified by mass spectrometry. The limit of detection can be as low as 8 × 10-10molL-1. This sorbent has a high absorption capacity (53.5μgmg-1) and shows good recoveries (90%). As many as 2145 phosphopeptides were isolated from 500μg tryptic digest of a rat liver lysate after enrichment by Ti-PA-MNPs. This is superior to that (1568 phosphopeptides) of commercial TiO2 kit. Graphical abstract Schematic presentation of fabrication for a novel modified magnetic nanomaterial (Ti-PA-MNPs) based on the chelation of phytic acid (PA) with Ti(IV) ions. Ti-PA-MNPs were successfully applied to enriching low abundance phosphopeptides from biosamples in mass spectrometric analysis.

Supported 4-carboxybenzyl sulfamic acid on magnetic nanoparticles as a recoverable and recyclable catalyst for synthesis of 3,4,5-trisubstituted furan-2(5H)-one derivatives

4-Carboxybenzyl sulfamic acid functionalized Fe3O4 nanoparticles as a novel catalyst was manufactured. This catalyst was characterized and evaluated in the one-pot synthesis of furan-2(5H)-one derivatives from dimethyl acetylenedicarboxylate, aryl aldehydes, and various anilines in terms of activity and reusability. The catalyst showed high catalytic activity, good recoverability and reusability, thermal stability and provides clean production of fine furan-2(5H)-one derivatives in short reaction times. The heterogeneous catalyst could be used at least five times without significant loss of its activity.

Palm Fatty Acid Functionalized Fe3O4 Nanoparticles as Highly Selective Oil Adsorption Material

The present work highlights the facile synthesis of hydrophobic palm fatty acid functionalized Fe3O4 nanoparticles (MNP-FA) for the efficient removal of oils from the surface of water. An intense hydrophobic layer was introduced on the surface of Fe3O4 nanoparticles functionalized by the palm fatty acid obtained from the hydrolysis of palm olein. Scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), Energy dispersive X-ray spectroscopy (EDX) and water contact angle analysis (WCA) measurements were used to characterize the newly fabricated palm fatty acid adorned magnetic Fe3O4 nanoparticles (MNP-FA). The obtained results confirmed the successful synthesis of palm fatty acid-functionalized magnetic nanoparticles. Oil removal tests performed with MNP-FA revealed that this newly prepared material could selectively adsorb lubricating oil up to 3.5 times of the particles' weight while completely repelling water. The main parameters affecting the adsorption of oil i.e., sorption time, mass of sorbent and pH of water were optimized.

Sensitive Determination of 6-Thioguanine Using Caffeic Acid-functionalized Fe3O4 Nanoparticles as an Electrochemical Sensor

The study demonstrates the potential application of caffeic acid-functionalized magnetite nanoparticles (CA-Fe3O4 NPs) as an effective electrode modifying material for the electrochemical oxidation of the 6-thioguanine (6-TG) drug. The functionalized Fe3O4 NPs were prepared using simple wet-chemical methodology where the used caffeic acid acted simultaneously as growth controlling and functionalizing agent. The study discusses the influence of an effective functionalization on the signal sensitivity observed for the electro-oxidation of 6-TG over CA-Fe3O4 NPs in comparison to a glassy carbon electrode modified with bare and nicotinic acid (NA)-functionalized Fe3O4 NPs. The experiment results provided sufficient evidence to support the importance of favorable functionality to achieve higher signal sensitivity for the electro-oxidation of 6-TG. The presence of favorable interactions between the active functional moieties of caffeic acid and 6-TG synergized with the greater surface area of magnetic NPs produces a stable electro-oxidation signal within the working range of 0.01–0.23 μM with sensitive up to 0.001 μM. Additionally, the sensor showed the strong anti-interference potential against the common co-existing drug molecules such as benzoic acid, acetaminophen, epinephrine, norepinephrine, glucose, ascorbic acid and l-cysteine. In addition, the successful quantification of 6-TG from the commercial tablets obtained from local pharmacy further signified the practical capability of the discussed sensor.

Synthesis and characterization of pyridine-4-carboxylic acid-functionalized Fe3O4 nanoparticles as a magnetic catalyst for the synthesis of tetrahydrobenzo[b]pyran derivatives under solvent-free conditions

ABSTRACTPyridine-4-carboxylic acid (PYCA)-functionalized Fe3O4 nanoparticles as an organic–inorganic hybrid heterogeneous catalyst was fabricated and characterized by Fourier transform infrared, X-ray powder diffraction, thermogravimetric analysis, transmission electron microscopy, scanning electron microscope, and VSM techniques. The catalytic activity of the magnetic catalyst was probed through one-pot synthesis of tetrahydrobenzo[b]pyran derivatives from three-component reactions of aromatic aldehydes, malononitrile, and dimedone under solvent-free conditions. Simple procedure, high yields, short reaction time, and environmentally benign method are advantages of this protocol. The catalyst was readily separated using an external magnet and was reusable without significant loss of its catalytic efficiency.

A pH-responsive folate conjugated magnetic nanoparticle for targeted chemo-thermal therapy and MRI diagnosis.

Polyacrylic acid functionalized Fe3O4 nanoparticles (PAA-MNPs) of average size of 10 nm are prepared by a simple soft chemical approach. These PAA-MNPs are conjugated with folic acid through peptide bonding between the carboxylic group on the surface of PAA-MNPs and the amine group of folic acid. The good colloidal stability of FA conjugated MNPs makes it a promising candidate for targeted drug delivery, hyperthermia and as a MRI contrast agent with a transverse relaxivity R2 value of 105 mM(-1) s(-1). Folic acid conjugated magnetic nanoparticles (FA-MNPs) achieved ∼ 95% loading efficiency of doxorubicin (DOX) which could be due to strong electrostatic interaction of highly negatively charged FA-MNPs and the positively charged DOX. The drug release study shows a pH-dependent behavior and is higher in acidic pH (4.3 and 5.6) as compared to the physiological pH (7.3). Flow cytometry and confocal microscopic image analysis reveal that around 75-80% of HeLa cells undergo apoptosis due to DNA disintegration upon incubation with DOX-MNPs for 24 h. DOX-MNPs exhibit the synergistic effect due to the combination of DOX induced apoptosis and magnetic hyperthermia treatment (MHT) which enhance the cell death ∼ 95.0%. Thus, this system may serve as a potential pH sensitive nanocarrier for synergistic chemo-thermal therapy as well as a possible MRI contrast agent.

Copper adsorption onto synthesized nitrilotriacetic acid functionalized Fe3O4 nanoparticles: kinetic, equilibrium and thermodynamic studies

The continuous discharge of heavy metals into the near water bodies causes great harm to the human and aquatic ecosystem. Several adsorbent have been developed and applied for effective removal of metal ions from water. In this paper nitrilotriacetic acid (NTA) functionalized Fe3O4 nanoparticles (Fe3O4-NTA) were developed by coprecipitation method with iron salt and NTA, shown to be effective removal of Cu(II) ions from aqueous solution. The functionalized nanoparticles were characterized by Fourier transform infrared spectroscopy (FTIR), X ray diffractometer (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscopy (AFM), Brunauer–Emmett–Teller Surface area analyzer (BET), and pHzpc. The various effecting factors of Cu(II) ions adsorption from aqueous solution such as contact time, adsorbate dose, and pH were investigated. The kinetics models such as pseudo-first-order, pseudo-second-order, Elovich, and intra-particles diffusion were applied on experimental Cu(II) adsorption. The kinetic data showed pseudo-second-order model was found to be better agreement with correlation coefficient, R2=0.997–0.999 at 60–12mgL−1. The equilibrium adsorption data modeled with Langmuir, Freundlich, and Dubinin–Radushkevich isotherms found to be better fitted with Langmuir reveal the monolayer adsorption of Cu(II) ions on the surface of Fe3O4-NTA with maximum adsorption capacity of 34.63, 38.8 and 40.24mgL−1 at 298, 303 and 308K, respectively. The positive value of ΔH° (35.127kJmol−1) and ΔS° (176.031kJmol−1K−1) indicates the endothermic nature of Cu(II) adsorption onto Fe3O4-NTA. The negative value of ΔG° (7.365–8.005kJmol−1) indicates spontaneous nature of adsorption.