APPLIED SURFACE SCIENCE
·
2016
·
IF 3.15
Xi-Lin Wu,Yanpeng Shi,Shuxian Zhong,Hongjun Lin,Jian-Rong Chen
Herein, we have developed a facile and low-cost method for the synthesis of novel graphene based nanosorbents. Firstly, well-defined Fe 3 O 4 nanoparticles were decorated onto graphene sheets, and then a layer of mesoporous SiO 2 were deposited on the surface of the Fe 3 O 4 -graphene composites. The obtained Fe 3 O 4 -graphene@mesoporous SiO 2 nanocomposites (denoted as MG@m-SiO 2 ) were characterized by scanning electron microscopic (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), Fourier transformed infrared (FTIR) spectroscopy and X-ray diffraction (XRD). The adsorptive property was investigated by using MG@m-SiO 2 as sorbents and Methylene Blue (MB), a common dye, as model of the organic pollutants. Adsorption kinetics, isotherms, thermodynamics as well as effects of pH and adsorbent dose on the adsorption were studied. The adsorption isotherms and kinetics are better described by Langmuir isotherm model and pseudo-second-order kinetic model, respectively. Thermodynamic studies suggest that the adsorption of MB onto the MG@m-SiO 2 is endothermic and spontaneous process. The results imply that the MG@m-SiO 2 can be served as a cost-effective adsorbent for the removal of organic pollutants from aqueous solutions.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Nanomaterials
·
2021
·
IF 2.986
Hongliu Jiang,Yao Cao,Fengtao Zeng,Zewu Xie,Fuan He
In this paper, a magnetic graphene oxide (MGO) composite was prepared by the click reaction between the alkyne-modified Fe3O4 nanoparticles and the azide-modified graphene oxide for the purpose of removing the Congo red (CR) dye from water. The deposition of the Fe3O4 nanoparticles on the graphene oxide to successfully prepare the MGO composite was evidenced by the Fourier-transform infrared spectrometer, wide-angle X-ray diffraction equipment, scanning electron microscope, thermal gravimetric analyzer, and Raman spectrometer. The value of saturation magnetization for the MGO composite was 34.9 emu/g. The CR absorption capacities of the MGO composite increased first and then decreased as the pH value increased. It was found that the maximum adsorption capacity of the MGO composite for the CR was as high as 769.2 mg/g. In the absorption-desorption experiment, the CR absorption capacities of the MGO composite from the second cycle to the fifth cycle remained stable to be about 130 mg/g. Moreover, both the Langmuir model for the adsorption isotherm and the pseudo-second-order kinetic model could be used to describe the CR absorption behaviors of the MGO composite.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
FOOD CHEMISTRY
·
2017
·
IF 4.529
Wenhua Ji,Mingming Zhang,Wenjuan Duan,Xiao Wang,Hengqiang Zhao,Lanping Guo
Phytic acid-stabilized Fe 3 O 4 -graphene oxide (GOPA@Fe 3 O 4 ) was assembled by microwave-enhanced hydrothermal synthesis and super-amphipathicity was demonstrated by measurement of dynamic oil and water contact angles. GOPA@Fe 3 O 4 was used as a sorbent for enrichment of eight polycyclic aromatic hydrocarbons (PAHs) from vegetable oils by magnetic solid-phase extraction (MSPE). The extraction-desorption factors were systematically investigated and, under optimum conditions, the super-amphiphilic sorbent achieved wide linear ranges (0.2–200 ng g −1 ), satisfactory precision (3.44–6.64% for intra-day and 5.39–8.41% for inter-day) and low limits of detection (LODs, 0.06–0.15 ng g −1 ) for PAHs. Excellent recoveries (85.6–102.3%) for spiked PAHs were obtained with genuine vegetable oil samples. These results indicate that MSPE using GOPA@Fe 3 O 4 as the sorbent, coupled with high performance liquid chromatography (HPLC), is an efficient and simple method for the detection of low concentrations of PAHs in vegetable oils.
研究领域:
分析化学
·
环境科学
·
食品科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2013
·
IF 3.172
Xiaoshu Lv,Xiaoqin Xue,Guangming Jiang,Donglei Wu,Tiantian Sheng,Hongyi Zhou,Xinhua Xu
Nanoscale Zero-Valent Iron (nZVI) assembled on magnetic Fe 3 O 4 /graphene (nZVI@MG) nanocomposites was synthesized for Cr(VI) removal from aqueous solution. nZVI particles were perfectly dispersed either among Fe 3 O 4 nanoparticles (Fe 3 O 4 NPs) or above the basal plane of graphene. This material shows Cr(VI) removal efficiency of 83.8%, much higher than those of individuals (18.0% for nZVI, 21.6% for Fe 3 O 4 NPs and 23.7% for graphene) and even their sum of 63.3%. The removal process obeys pseudo-second-order adsorption model, suggesting that adsorption is rate-controlling step. Maximum Cr(VI) adsorption capacity varies from 66.2 to 101.0 mg g −1 with decreasing pH from 8.0 to 3.0 at 30 °C. Negative Δ G and Δ H indicate spontaneous tendency and exothermic nature. Robust performance of nZVI@MG arises from the formation of micro-nZVI-graphene/nZVI-Fe 3 O 4 batteries and strong adsorption capability of broad graphene sheet/Fe 3 O 4 surfaces. Electrons released by nZVI spread all over the surfaces of graphene and Fe 3 O 4 , and the adsorbed Cr(VI) ions on them capture these floating electrons and reduce to Cr(III). Fe 3 O 4 NPs also served as protection shell to prevent nZVI from agglomeration and passivation.
研究领域:
环境科学
·
材料科学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF PHARMACEUTICAL AND BIOMEDICAL ANALYSIS
·
2018
·
IF 2.831
Zhaokun Wang,Pengfei Zhao,Bolin Zhu,Zhen Jiang,Xingjie Guo
In this work, a nanocomposite, Fe 3 O 4 /graphene was prepared and characterized. Five profens (including ibuprofen, flurbiprofen, pranoprofen, indoprofen and loxoprofen sodium) were extracted from three environmental water samples by using the synthetic Fe 3 O 4 /graphene, followed by simultaneous determination of the enantiomers on a Chiralcel OJ-RH column coupled with a triple quadrupole mass spectrometry. Factors affecting the extraction efficiency, such as amount of adsorbents, solution pH, ionic strength, type and volume of desorption solvent, as well as elution time were thoroughly investigated. Method validation showed high sensitivity with method quantification limits in the range of 8.49–26.3 ng/L. Satisfactory recovery (73.6–90.2%), good intra-day precision (RSD 3.2–9.7%) and inter-day precision (RSD 5.2–10%) were also obtained. Furthermore, possible interactions between analyte and graphene, such as electrostatic attraction, charge-π interaction, hydrophobic interaction and π-π stacking were discussed by combining the experiment results and molecular docking study, which provided a new insight into the adsorption mechanism of graphene.
研究领域:
分析化学
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环境科学
·
药物分析
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2013
·
IF 2.591
Xiaoji Cao,Jiaoyu Chen,Xuemin Ye,Feifei Zhang,Lingxiao Shen,Weimin Mo
An ultrasound-assisted magnetic SPE procedure with an Fe 3 O 4 -grafted graphene nanocomposite as the magnetic adsorbent has been developed to determine seven polychlorinated biphenyls (PCBs; PCB28, PCB52, PCB101, PCB118, PCB138, PCB153, and PCB180) simultaneously in 200 mL environmental water samples, in combination with GC–MS/MS. Several factors related to magnetic SPE efficiencies, such as the superparamagnetic intensity and amount of adsorbent, extraction time, sample pH, and desorption conditions were investigated. With the assistance of ultrasound, the extraction achieved the maximum within only 20 s, attributed to the powerful adsorptive ability of the magnetic adsorbent toward the PCBs. Under the optimized conditions, an excellent linearity was observed in the range of 0.1–100 ng/L for PCB28, 0.2–100 ng/L for PCB52, and 0.5–100 ng/L for the other five PCBs with the correlation coefficients ranging from 0.9988 to 0.9996. The mean recoveries at spiked levels of 5.0 and 10.0 ng/L were 84.9–108.5%, the coefficients of variations were <6.5%. With convenient magnetic separation, the synthesized magnetic adsorbent could be recycled more than ten times. The proposed method was demonstrated to be feasible, simple, rapid, and easy to operate for the trace analysis of the PCBs in environmental water samples.
研究领域:
环境科学
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分析化学
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产品关联
DOI
PubMed
高影响因子
JOURNAL OF SEPARATION SCIENCE
·
2020
·Vol. 43
·期 17
·3499-3508
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IF 2.878
Yinan Guo,Wei Wei,Ying Zhang,Yuanyuan Dai,Weiping Wang,Aijun Wang
An aptamer (Apt) functionalized magnetic material was prepared by covalently link Apt to Fe 3 O 4 /graphene oxide (Fe 3 O 4 /GO) composite by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride and N -hydroxysuccinimide, and then characterized by FTIR spectroscopy, X-ray diffraction, and vibration sample magnetometry. The obtained composite of Fe 3 O 4 /GO/Apt was employed as magnetic solid-phase extraction adsorbent for the selective preconcentration of sulfadimethoxine prior to analysis by high-performance liquid chromatography. Under the optimal conditions (sample pH of 4.0, sorbent dosage of 20 mg, extraction time of 3 h, and methanol-5% acetic acid solution as eluent), a good linear relationship was obtained between the peak area and concentration of sulfadimethoxine in the range of 5.0 to 1500.0 µg/L with correlation coefficient of 0.9997. The limit of detection ( S/N = 3) was 3.3 µg/L. The developed method was successfully applied to the analysis of sulfadimethoxine in milk with recoveries in the range of 75.9-92.3% and relative standard deviations less than 8.1%. The adsorption mechanism of Fe 3 O 4 /GO/Apt toward sulfadimethoxine was studied through the adsorption kinetics and adsorption isotherms, and the results show that the adsorption process fits well with the pseudo-second-order kinetic model and the adsorbate on Fe 3 O 4 /GO/Apt is multilayer and heterogeneous.
研究领域:
分析化学
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环境科学
·
食品安全
✓ 已验证
产品关联
DOI
PubMed
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2015
·
IF 6.409
Yulan Wang,Hongmin Ma,Xiaodong Wang,Xuehui Pang,Dan Wu,Bin Du,Qin Wei
An ultrasensitive sandwich-type electrochemical immunosensor based on a novel signal amplification strategy was developed for the quantitative determination of human immunoglobulin G (IgG). Pd nanocubes functionalized magnetic graphene sheet (Pd–Fe 3 O 4 -GS) was employed as the matrix to immobilize the primary antibodies (Ab 1 ). Owing to the synergetic effect between Pd nanocubes and magnetic graphene sheet (Fe 3 O 4 -GS), Pd–Fe 3 O 4 -GS can provide an obviously increasing electrochemical signal by electrochemical catalysis towards hydrogen peroxide (H 2 O 2 ). Silicon dioxide (SiO 2 ) was functionalized as the label to conjugate with the secondary antibodies (Ab 2 ). Due to the larger steric hindrance of the obtained conjugate (SiO 2 @Ab 2 ), the sensitive decrease of the electrochemical signal can be achieved after the specific recognition between antibodies and antigens. In this sense, this proposed immunosensor can achieve a high sensitivity, especially in the presence of low concentrations of IgG. Under optimum conditions, the proposed immunosensor offered an ultrasensitive and specific determination of IgG down to 3.2 fg/mL. This immunoassay method would open up a new promising platform to detect various tumor markers at ultralow levels for early diagnoses of different cancers.
研究领域:
生物医学工程
·
分析化学
✓ 已验证
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2015
·Vol. 18
·期 2
·718-725
·
IF 4.493
Fangfang Chen,Weifeng Zhao,Jingjing Zhang,Jie Kong
Surface molecular imprinting for proteins is an emerging cross-field of molecular imprinting engineering and functional materials. In this contribution, we report a novel design of magnetic two-dimensional molecularly imprinted polymers (2D-MIPs) for the high recognition and separation of proteins. Bovine serum albumin-surface-imprinted polydopamines were prepared on the surfaces of the magnetic Fe3O4–graphene oxide hybrid to form magnetic 2D-MIPs for proteins. The 2D Fe3O4–graphene oxide substrate possesses a dominant surface-to-volume ratio in comparison to 3D spherical substrates with the same volume. These materials are sensitive to a magnetic field and can be easily separated using an external magnet. The binding experimental results of bovine serum albumin on magnetic 2D-MIPs and real sample analysis demonstrated the high recognition specificity, selectivity, accessibility and convenient separation of 2D-MIPs for template protein. The design and synthesis of magnetic 2D-MIPs provide a new perspective for the surface molecularly imprinted materials with potential in the recognition and separation of proteins.
研究领域:
生物材料学
·
分子识别工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ACS Applied Materials & Interfaces
·
2016
·
IF 7.145
Zhigang Liu,Yi Wang,Rong Deng,Liyuan Yang,Shihua Yu,Shuping Xu,Weiqing Xu
A multifunctional magnetic graphene surface-enhanced Raman scattering (SERS) substrate was fabricated successfully by the layer-by-layer assembly of silver and graphene oxide (GO) nanoparticles (NPs) on the magnetic ferroferric oxide particles (Fe3O4@GO@Ag). This ternary particle possesses magnetic properties, SERS activity, and adsorption ability simultaneously. Owing to the multifunction of this Fe3O4@GO@Ag ternary complex, we put forward a new method called a surface magnetic solid-phase extraction (SMSPE) technique, for the SERS detections of pesticide residues on the fruit peels. SMSPE integrates many sample pretreatment procedures, such as surface extraction, separation sample, and detection, all-in-one. So this method shows great superiority in simplicity, rapidity, and high efficiency above other standard methods. The whole detection process can be finished within 20 min including the sample pretreatment and SERS detection. Owing to the high density of Ag NPs, the detection sensitivity is high enough that the lowest detectable concentrations are 0.48 and 40 ng/cm2 for thiram and thiabendazole, which are much lower than the maximal residue limits in fruit prescribed by the U.S. Environmental Protection Agency. This multifunctional ternary particle and its corresponding analytical method have been proven to be applicable for practical samples and also valuable for other surface analysis.
研究领域:
分析化学
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环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2021
·
IF 7.514
Zi-Tao Zhong,Hai-Bo Wang,Ting Zhang,Chao-Qing Li,Bo Liu,Yuan-Di Zhao
Pregnancy test strips are one of the most mature and widely used commercial lateral flow devices used to determine pregnancy. Being a simple and rapid detection method, human chorionic gonadotropin (hCG) was used with different aptamers (hCG-apt) as probes for the detection of metal ions, small organic molecules, and proteins. Quantitative detection of target analytes was achieved using a smartphone app and a portable device developed in our laboratory. The results showed detection ranges of 1 nM−1 μM, 0.1 nM–10 μM and 32 nM–500 nM for Pb 2+ , chloramphenicol, and β-lactoglobulin, respectively, and the corresponding visual detection limits in dairy products were 5 nM, 1 nM and 50 nM, respectively. Based on these results, rapid detection of multiple analytes can be realized through aptamer modification, thereby broadening the application range of commercial lateral flow devices for analysis of food chemistry.
研究领域:
分析化学
·
食品科学
·
生物技术
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2021
·
IF 10.588
Lin Wang,Qiya Sun,Yicheng Dou,Zhipeng Zhang,Tingting Yan,Yongmei Li
A novel ternary recyclable Fe 3 O 4 /graphene/sulfur-doped g-C 3 N 4 (Fe 3 O 4 /GE/SCN) composite catalyst was synthesized and adopted in a visible-light driven catalytic system for the degradation of ranitidine, which is an important precursor of the emerging disinfection by-product of N-nitrosodimethylamine (NDMA). The addition of GE and Fe 3 O 4 significantly improved the interface charge transfer of SCN, increased the light collection efficiency and decreased the photogenerated charge recombination efficiency. Considering both the ranitidine removal efficiency and catalyst recovery, the Fe 3 O 4 mass fraction of 20% (20%-Fe 3 O 4 /GE/SCN) was recommended. Ranitidine (≤ 2 mg/L) was completely removed in 60 min under the conditions of an initial pH of 7.0 and a 20%-Fe 3 O 4 /GE/SCN dose of 1.0 g/L, and its degradation fitted well with the pseudo first-order kinetics model. Electron paramagnetic resonance analysis and trapping experiments confirmed that ·O 2 − , ·OH and h + participated in the degradation of ranitidine. Ranitidine was removed through the pathways of demethylation and hydroxylation based on the analysis of the detected degradation intermediates, and 57.3% of the NDMA formation potential (FP) was reduced after the reaction. The visible-light driven 20%-Fe 3 O 4 /GE/SCN catalytic technology is a promising method not only for the control of NDMA FP but also the catalyst could be recovered and reused.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
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