Magnetic Graphene Oxide Nanocomposite Research Articles

Magnetically Purification/Immobilization of Poly Histidine-Tagged Proteins by PEGylated Magnetic Graphene Oxide Nanocomposites

Magnetically Purification/Immobilization of Poly Histidine-Tagged Proteins by PEGylated Magnetic Graphene Oxide Nanocomposites

MAGNETIC NANOPARTICLES AND IONIC LIQUID EFFECT ON ELECTROCHEMICAL SENSORS PERFORMANCE

Magnetic nanoparticles and ionic liquid (IL, 1-hexyl-3-methyl-imidazolium bromide) based on graphene oxide (GO) composite provide unique physical and chemical properties in electrochemical sensors performance. Magnetic nanoparticles can cover active sites that increase chemical reactions with easy separation. IL increases the scan rate of electron transfer between the modified electrode and solution because it includes conductive adhesion properties. Also, IL in the next steps of design carbon paste electrodes (CPE) increases the cohesion. The study aims are to study the effects of magnetic nanoparticles and IL on the electrochemical detection of dopamine (DA). DA has a vital role in the mammalian central nervous system and change its value from the standard range leads broad mental diseases. But magnetic graphene oxide (MGO) may not exist capable of enhancing electrochemical signs alone. In this regard, after the synthesis of MGO, IL was established on composite. Then gold nanoparticles (AuNPs) and molecularly imprinted polymer (MIP) were modified MGO nanocomposite. MIP polymerization was continued by methacrylic acid (MAA) in the presence of DA as a template molecule. The developed sensor with modified nanocomposite studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The modified sensor based on nanocomposite with a broad concentration linear range, between 1×10-7 to 1×10-4 M and a limit of detection of 1×10-8 M (S/N=3) was used for the detection of DA in biological samples. Furthermore, these results prove that MGO was improved active sites of surface nanocomposite and IL was increased conductivity in the based electrochemical sensor for DA detection.

Determination of EGFR-overexpressing tumor cells by magnetic gold-decorated graphene oxide nanocomposites based impedance sensor

This work developed an electrochemical impedance spectroscopy (EIS) sensor for detection of EGFR (epidermal growth factor receptor)-overexpressing tumor cell and preliminary estimation of EGFR expression. Here, EGFR antibodies as the specific antibodies for cancer cells were conjugated on magnetic gold-decorated graphene oxide nanocomposites, which were used to capture the EGFR-overexpressing tumor cells. The magnetically responsive tumor cells were enriched and immobilized on a magnetic glassy carbon electrode (mGCE) surface, leading to increased electron-transfer resistance (Ret) utilized for determination of cells and preliminary evaluation of EGFR expression level. This strategy enables the enrichment, fixation and detection of tumor cells to be accomplished in a facile way. An excellent linearity in the range of 2.0 × 102 − 3.0 × 105 cell mL−1 with the detection limit of 152 cell mL−1 for MDA-MB-231 cells was obtained. Investigation on the expression levels of EGFR on various types of cells was conducted. MDA-MB-231 cells showed a distinctly higher EGFR expression, compared with MHCC97-L and L02 cells, providing the possibility for the EGFR-targeted therapy of the tumors. It is expected that the proposed sensor has the potential to be applied for cancer monitoring.

Highly Efficient Adsorption and Removal of Amoxicillin from Aqueous Solution by Magnetic Graphene Oxide Nanocomposite

Background: Antibiotics have lasting effects on the environment. Among the properties of these substances are non-biodegradable, carcinogenic, high toxicity, and an increase in antibiotic-resistant bacteria. Therefore, they should be removed from aqueous solutions and the point of this think was to adsorb amoxicillin (AMO) by magnetic graphene oxide nanocomposite (MGO). Methods: The adsorption behavior of AMO was studied in a series of batch experiments as a function of pH (3-11), contact time (0-120 min), and AMO concentration (10-100 mg/L) different MGO dosages (0.1-1 g/L). The structures of MGO were confirmed by scanning electron microscope (SEM), and the X-ray diffraction (XRD). Results: The results revealed in optimized conditions (pH=3, contact time=75 min, AMO concentration= 10mg/L and adsorbent dose=0.75 g/L) maximum adsorption capacity and removal efficiency of AMO were 98.41 mg/g, respectively. The thermodynamical parameters showed that the sorption method was endothermal and spontaneous. Conclusion: MGO nanoparticles have extended capabilities such as easy and rapid separation from solution and high potential in removing AMO, so, it can be introduced as an appropriate adsorbent for removal of this antibiotics from water and wastewater.

Facile synthesis of DTC-Chm-GO nanocomposite with remarkable adsorption capacity and antibacterial activity

In this study, a novel dithiocarbamate functionalized magnetic chitosan graphene oxide (DTC-Chm-GO) nanocomposite was synthesized for the first time and used for simultaneously dyes and heavy metal ions adsorption as well as bacterial disinfection in complex wastewater. The maximum adsorption capacities of DTC-Chm-GO for the four pollutants calculated from Langmuir isotherm were 507.61, 520.83, 416.67, 349.65 mg·g−1 for methylene blue (MB), crystal violet (CV), Pb2+, Cu2+, respectively, which was attributed to the abundant functional groups on the surface of DTC-Chm-GO. Besides, the adsorption mechanism of MB was dependent on electrostatic interaction, π-π interaction and cation-π interaction, while Pb2+ removal mechanism could be related with electrostatic interaction and coordinate covalent bonds. In addition, the synthesized DTC-Chm-GO nanocomposite exhibited excellent antibacterial activity towards both E. coli and S. aureus. Thus, the DTC-Chm-GO could be an ideal candidate in environmental remediation, intelligent separation, bacterial inactivation and so on.

Effective Detoxification of Aflatoxin B1 and Ochratoxin A Using Magnetic Graphene Oxide Nanocomposite: Isotherm and Kinetic Study

One of the approaches for reducing exposure to mycotoxins is to lessen their bioavailability by applying nanocomposite adsorbents. Magnetic graphene oxide (MGO) is a new class of nanostructured multifunctional nanocomposite materials, which play a vital role as an adsorbent. The primary aim of this study is to apply response surface methodology (RSM) to optimize the influence of pH within the range of 3 to 7, time (3–7 h), and temperature (30–50 °C), on the simultaneous detoxification of aflatoxin B1 (AFB1) and ochratoxin A (OTA) by using MGO. The optimal condition was obtained at pH 5, 5 h, and 40 °C. Further investigation of the adsorption evaluation was carried out by studying different parameters, such as the influence of contact time, initial mycotoxins concentration, and temperature. According to the experimental data, it can be concluded that the pseudo-second-order kinetic model and the Freundlich isotherm fitted well. The capability of adsorption for the Freundlich model was calculated as 153 and 95 ng/g for AFB1 and OTA, respectively. The thermodynamic study showed that the sorption studies act spontaneously as an exothermic process. These findings suggest that the application of MGO as a nanocomposite is of great significance for the detoxification of mycotoxins.

Determination of lamotrigine by fluorescence quenching of N-doped graphene quantum dots after its solid-phase extraction using magnetic graphene oxide

A sensitive fluorescent nanoprobe is reported for the determination of lamotrigine after its preconcentration by magnetic graphene oxide nanocomposite. The fluorescent nanoprobe is based on the quenching effect of lamotrigine on the nitrogen graphene quantum dots fluorescence at 440 nm, through strong hydrogen bonding. Under optimum conditions, the quenching fluorescent intensity of nitrogen graphene quantum dots shows linearity with the lamotrigine concentration in the range of 2.0–45.0 µg L−1, limits of detection (LOD), and quantification of 0.39 and 1.28 µg L−1 respectively. The parameters affecting the extraction and determination of lamotrigine were optimized via the central composite design (CCD) and one at the time method, respectively. The developed method was successfully employed for the extraction and quantification of lamotrigine in biological samples.

Catalytic dehydration of fructose into 5-hydroxymethylfurfural by propyl sulfonic acid functionalized magnetic graphene oxide nanocomposite

Covalent immobilization of propyl sulfonic acid groups on the surface of magnetic graphene oxide is reported as an efficient magnetically recoverable solid acid catalyst for the conversion of fructose into 5-hydroxymethylfurfural (5-HMF). The obtained nanocomposite has advantages of both graphene oxide (high surface area) and magnetic nanoparticles (fast and facile separation by a magnet). The numerous reaction parameters including solvent, reaction time, temperature, and amount of catalyst were optimized to attain maximum yield of 5-HMF. The results revealed that fructose could be effectively transformed into 5-HMF with a yield of 87% under the optimized reaction conditions. The catalyst could be magnetically separated from the reaction mixture. Moreover, the catalyst exhibited high stability and could be reused for at least five times without a discernible loss of catalytic performance.

Effective Detoxification of Aflatoxin B1 and Ochratoxin A using Magnetic Graphene Oxide Nanocomposite: Isotherm and Kinetic Study

Effective Detoxification of Aflatoxin B1 and Ochratoxin A using Magnetic Graphene Oxide Nanocomposite: Isotherm and Kinetic Study

Triformyl cholic acid and folic acid functionalized magnetic graphene oxide nanocomposites: Multiple-targeted dual-modal synergistic chemotherapy/photothermal therapy for liver cancer

Photo-chemotherapy (PCT) reveals great potential in hepatocellular carcinoma (HCC) treatment, therefore the construct of smart PCT nano-agents with high photothermal conversion efficiency and accurate drug delivery is of great significant. Herein, a novel hybrid nanomaterial MGO-TCA-FA has been designed and constructed by grafting the triformyl cholic acid (TCA) and folic acid (FA) on the surface of Fe3O4 modified graphene oxide (MGO). The doxorubicin hydrochloride (DOX) as a model drug could be effectively loaded on the MGO-TCA-FA via hydrogen bonding and π-π stacking (the drug loading amount was 1040 mg/g). The formed MGO-TCA-FA@DOX has been developed to be an effective PCT nanoplatform with the advantages of multiple-targeted drug delivery, near-infrared light (NIR) and pH triggered drug release, and photothermal conversion efficiency. In vitro experiments showed that compared with other cancer cells and normal liver cells, MGO-TCA-FA@DOX could specifically target liver cancer cells and presented significant killing ability to liver cancer cells. More importantly, in vivo experiments indicated that PCT synergistic therapy (MGO-TCA-FA@DOX) revealed the best tumor inhibition (the tumor inhibition rate was about 85%) compared with chemotherapy and photothermal therapy alone. Thus, this study supplied a viable multiple-targeted PCT nano-agent for chemo-photothermal combination therapy of liver cancer.

Reusable ionic liquid functionalized magnetic graphene oxide nanocomposite as magnetic dispersive solid phase extraction sorbent to preconcentrate polychlorinated biphenyls in seafood

Reusable ionic liquid functionalized magnetic graphene oxide nanocomposite as magnetic dispersive solid phase extraction sorbent to preconcentrate polychlorinated biphenyls in seafood

A novel dispersive magnetic solid phase microextraction using ionic liquid-coated amino silanized magnetic graphene oxide nanocomposite for high efficient separation/preconcentration of toxic ions from shellfish samples

A novel dispersive magnetic solid phase microextraction (d-MSPE) method using ionic liquid-coated amino silanized magnetic graphene oxide (MGO@SiO2-APTES-IL) as adsorbent has been established for enriching and extracting lead(II), copper(II) and cadmium(II) in shellfish samples. The novel nanocomposite was proved synthesized successfully by various characterization technologies. Parameters that could affect the recoveries of target ions were investigated and optimized focusing on adsorption and desorption using Box-Behnken design of response surface methodology (BBD-RSM). The limits of detection (LODs) for three target heavy metal ions were 2.42, 3.36, 3.75 ng L-1, respectively. Additionally, the maximum adsorption capacities of the nanocomposite for target ions were 251.23, 138.51, 159.31 mg g−1 at 298 K, respectively, the nanoadsorbent can be regenerated without significant adsorption capacities loss for four times. These observations revealed that the novel nanocomposite can be used as an excellent adsorbent for separation and preconcentration of the target ions.

Magnetic graphene oxide nanocomposite: One-pot preparation, adsorption performance and mechanism for aqueous Mn(Ⅱ) and Zn(Ⅱ)

Excessive discharge of heavy metals by industrial activities has caused severe environmental problem. In this work, a magnetic graphene oxide nanocomposite (MGON) based on graphene oxide-Fe3O4 framework was prepared, characterized and employed as adsorbent to remove aqueous Mn(Ⅱ), Zn(Ⅱ) efficiently. The adsorption performance and mechanism were investigated carefully. Results suggest, the mutual enhancement between GO and Fe3O4 brings synergistic effect on adsorption performance, which enables MGON to outperform either of the two single phase. In particular, MGON efficiently adsorbs 399.67 mg g−1, 372.98 mg g−1 of Mn(Ⅱ), Zn(Ⅱ) in 4 min, 6 min, respectively. What is more, MGON can be readily recovered via magnetic separation for further recycling. The thermodynamic parameters of the adsorptions under 298.15 K are: ΔH = 20.86 kJ mol−1, ΔS = 108.84 J K−1 mol−1, ΔG = −11.59 kJ mol−1 for Mn(Ⅱ) and ΔH = 20.99 kJ mol−1, ΔS = 96.04 J K−1 mol−1, ΔG = −7.64 kJ mol−1 for Zn(Ⅱ), respectively, indicating spontaneous, endothermic and entropy increasing features. Both adsorptions fit well by the Freundlich, pseudo second order, and intra-particle diffusion models. Furthermore, adsorption mechanism is based on the chemical interaction of the oxygen atoms in CO, C-O related groups with Mn(Ⅱ), Zn(Ⅱ). The high adsorption efficiency suggests that MGON has promising application in heavy metal treatment.

Preparation and characterization of magnetic graphene oxide nanocomposite (GO-Fe3O4) for removal of strontium and cesium from aqueous solutions

Magnetic graphene oxide nanocomposites (M-GO) were successfully synthesized by partial reduction co-precipitation method and used for removal of Sr(II) and Cs(I) ions from aqueous solutions. The structures and properties of the M-GO was investigated by X-ray diffraction, Fourier transformed infrared spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, scanning electron microscopy, vibrating sample magnetometer (VSM) and N2-BET measurements. It is found that M-GO has 2.103 mg/g and 142.070 mg/g adsorption capacities for Sr(II) and Cs(I) ions, respectively. The adsorption isotherm matches well with the Freundlich for Sr(II) and Dubinin–Radushkevich model for Cs(I) and kinetic analysis suggests that the adsorption process is pseudo-second-ordered.

Equilibrium and kinetics studies of naproxen adsorption onto novel magnetic graphene oxide functionalized with hybrid glycidoxy-amino propyl silane

A hybrid silica-gel (3-glycidoxypropyl)trimethoxysilane/(3-aminopropyl)triethoxysilane magnetic graphene oxide (GPTMS/APTMS-MGO) nanocomposite was synthesized and used as an adsorbent for the magnetic removal of naproxen from water samples. The adsorbent was characterized using Fourier transform-infrared (FT-IR) spectroscopy, field emission-scanning electron microscopy (FE-SEM), energy-dispersive X-ray (EDX) spectroscopy, and transmission electron microscopy (TEM). The isotherm and kinetic studies showed that the data were fitted with Langmuir isotherm and pseudo-second-order kinetic models. The high adsorption capacity of 196 mg g−1 was obtained that indicated a monolayer sorption mechanism. The method was successfully applied for the removal of naproxen from wastewater samples and the removal efficiencies of 84–95% were obtained.

Ultrasound-assisted magnetic solid-phase extraction of polycyclic aromatic hydrocarbons and nitrated polycyclic aromatic hydrocarbons from water samples with a magnetic polyaniline modified graphene oxide nanocomposite

A novel magnetic graphene oxide nanocomposite modified with polyaniline (Fe3O4@GO-PANI) was synthesized and applied for the magnetic solid-phase extraction of polycyclic aromatic hydrocarbons (PAHs) (i.e. fluorene, phenanthrene and pyrene) and nitrated polycyclic aromatic hydrocarbons (N-PAHs) (i.e. 2-nitrofluorene, 9-nitroanthracene, 1-nitropyrene and 3-nitrofluoranthene) prior to their determination by gas chromatography-mass spectrometry. The prepared nanomaterial was characterized by scanning electron microscopy, X-ray diffraction, and Fourier transform-infrared spectroscopy. The main experimental parameters affecting the extraction and desorption steps of the MSPE procedure were investigated and optimized. Under optimum conditions, coefficients of determination (r2) ranged between 0.9970 and 0.9995, limits of detection (LODs, S/N = 3) ranged between 0.04–0.05 ng mL−1 for PAHs and 0.01–0.11 ng mL−1 for N-PAHs, while the relative standard deviation for intra-day and inter-day repeatability were lower than 10.0% for PAHs and N-PAHs. The method was successfully applied to the analysis of tap, mineral and river water samples. Relative recoveries in spiked water samples ranged between from 91.6 to 114% and from 92.3 to 110% for PAHs and N-PAHs, respectively. The proposed method is simple, rapid, sensitive and the Fe3O4@GO-PANI sorbent can be reused for at least 15 times without significant decrease in extraction recovery.

Development of a D-μSPE method based on curcumin-modified magnetic reduced graphene oxide nanocomposite for the determination of Trichostatin A in a biological sample

ABSTRACT In the current work, a novel curcumin-modified magnetic graphene oxide nanocomposite was synthesised through a facile method and the loading of Trichostatin A as an anticancer drug was evaluated. D-μSPE method coupled with high-performance liquid chromatography (HPLC-DAD) successfully applied to determine the target analyte. The proper synthesis of the nanocomposite was investigated using Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy and vibrating sample magnetometry. The Taguchi statistical design was used to investigate the impact of five operating variables. The results for signal/noise ratio (S/N) and analysis of variance showed that the MG-curcumin/TSA ratio was the most significant factor while the solution pH was the least significant variable. In addition, the optimum operating conditions were obtained and adsorption isotherms were also studied. The optimised parameters were employed to perform extraction of the TSA from real samples. Good linearity (with r 2 = 0.9950) was shown for TSA concentrations from 5.0 to 1000.0 ng mL−1. Moreover, detection limit (0.70 ng mL−1), limit of quantification (2.51 ng mL−1), Inter-day and intra-day precision (n = 5, 3.2%, and 5.0%) were achieved for the method.

β-Cyclodextrin-grafted magnetic graphene oxide nanocomposites in ultrasound-assisted dispersive magnetic solid-phase extraction for simultaneous preconcentration of lead and cadmium ions

This article presents an ultrasound-assisted dispersive magnetic solid-phase extraction method (USA-DMSPE) to preconcentration Cd(II) and Pb(II) simultaneously. The adsorbent (mGO-βCD) was synthesized through three steps with consumption of environmentally friendly materials at room temperature. First graphene oxide (GO) was prepared via modified Hummer’s method and then magnetized by Fe3O4 precipitation (mGO). Finally, β-cyclodextrin was covalently immobilized onto the surface of mGO. X-ray diffraction patterns established pure crystallinity of the materials. Homogenous distribution of magnetic nanoparticles onto GO sheets was confirmed by scanning electron microscopy and transmission electron microscopy. FT-IR spectra proved successful modification of mGO by β-CD. Alternating gradient force magnetometer characterized magnetic property. Brunauer–Emmett–Teller showed porous structure of mGO-βCD and having high surface area. pH (7 ± 0.2), adsorption time (2 min), adsorbent amount (20 mg), eluent kind (HNO3 (3 ml of 2.0 mol L−1)) and desorption time (one minute) were optimum conditions. Sonication disperses adsorbent in sample solution, which accelerates mass transfer, as well as decreasing adsorption time and adsorbent usage amount. Applicability of the method was investigated according to preconcentration factor (Pb(II): 200 and Cd(II): 167), linearity of dynamic range (Pb(II): (2–410) and Cd(II) (3–400 μg L−1), limit of detection (Pb(II): 0.64 and Cd (II): 0.9 μg L−1), relative standard deviation (Pb(II): 1.68% and Cd(II): 2.51%) and adsorption capacity (Pb(II): 188.68 and Cd(II): 78.12). mGO-βCD was reusable for ten times and durable in six months. Selectivity and effect of interference ions were reported. Obtained recoveries for real samples verified the satisfactory performance of the method.

Facile synthesis of layer-by-layer decorated graphene oxide based magnetic nanocomposites for β-agonists/dyes adsorption removal and bacterial inactivation in wastewater

The escaped β-agonists and dyes during conventional wastewater treatment processes pose a non-negligible threat to humans and environment. In this study, a novel method based on the thiol modified chitosan magnetic graphene oxide nanocomposite (Fe3O4@SiO2/GO/CS/MPTS) was reported for the effective removal of β-agonists and dyes as well as the disinfection of microorganisms in complex wastewater. The surface and textural properties of the nanocomposites were characterized through Fourier transform infrared spectrums (FT-IR), scanning electron micrographs (SEM), X-ray photoelectron spectra (XPS), vibrating sample magnetometry (VSM) and zeta-potential measurements analysis. And the influence of several parameters (pH, contact time, pollutants concentration and adsorbent dose) on the adsorptive performances of nanoparticles was carefully estimated by the batch adsorption studies. According to Langmuir isotherm, the maximum adsorption capacities of Fe3O4@SiO2/GO/CS/MPTS were 215.52, 263.85, 184.16, 558.66 and 613.50 mg g−1 for dopamine (DA), clenbuterol (CLE), orciprenaline (ORC), methylene blue (MB) and crystal violet (CV), respectively. The data of the adsorption kinetic and adsorption isotherm fitted well with pseudo-second order kinetic and Langmuir isotherm models, which indicating the existence of chemical adsorption and monolayer adsorption process. The adsorption mechanisms of β-agonists and dyes were ascribe to electrostatic interaction, π–π interaction and cation− π interaction. Moreover, the nanocomposite could be reused for four cycles for β-agonists and five cycles for dyes with minor loss of adsorption capacity. In addition to its excellent adsorption capacity, the as-prepared nanocomposite exhibited the highest antibacterial activity of 88.94% and 100% against E. coli and S. aureus at the nanomaterial concentration of 75 μg mL−1, as compared to GO showing 31.67% and 26.87% antibacterial activity for E. coli and S. aureus, respectively. Predictably, this magnetic nanomaterial with high adsorption efficiency and excellent antibacterial activity provided a potential method for the removal of pollutants and inactivation of bacterial in wastewater.

Synthesis and optimization of a green and efficient sorbent for removal of three heavy metal ions from wastewater samples: kinetic, thermodynamic, and isotherm studies

A novel, green, and stable sorbent (Fe3O4@SiO2@l-Cysteine functionalized magnetic graphene oxide nanocomposites) was synthesized based on a chemical procedure to remove chromium(VI), lead(II), and cadmium(II) ions from wastewater samples. The l-Cysteine functionalized magnetic graphene oxide as a sorbent component was prepared based on the formation of the covalent bonding between graphene oxide and l-Cysteine. The percentages of the sorbent components, including Fe3O4 NPs, SiO2, and C-FGO were optimized using a D-optimal mixture design to enhance the sorbent stability, selectivity, and affinity toward the heavy metal ions. Besides, the critical factors on the heavy metal ion adsorption were investigated and optimized by a two-level full factorial central composite design. Electrostatic attraction is responsible for the adsorption of these ions on the sorbent, which is highly dependent on pH value. The kinetic study shows that the adsorption of these metal ions onto the sorbent follows the pseudo-second-order rate. The experimental results were investigated using the Freundlich and Langmuir models to determine the isotherm model, indicating the Freundlich isotherm model can well describe the adsorption procedure on the sorbent. The maximum adsorption capacity of 476.19, 526.32, and 588.23 mg g−1 was calculated for the Cr(VI), Pb(II), and Cd(II) ions with favorable adsorption and high affinity, respectively. The study of thermodynamic parameters indicates that the adsorption of these ions onto the sorbent is endothermic and chemical in nature. Moreover, the adsorption process is spontaneous in the temperature range of 278–328 K for removing these heavy metal ions. The obtained results confirm that the proposed sorbent is very suitable for the removal of the Cr(VI), Pb(II), and Cd(II) ions from electroplating wastewater samples with many advantages such as high efficiency, environment-friendly, low cost, and short absorption time.