APPLIED CATALYSIS B-ENVIRONMENTAL
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2019
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IF 14.229
Yibin Bu,Yafeng Chen,Guiming Jiang,Xinmei Hou,Shun Li,Zuotai Zhang
To design an efficient catalyst for HCHO oxidation, it requires good understanding of the correlation between structural properties of catalyst and the reaction mechanism. We investigated performance of commercial CeO 2 (CeO 2 -C) and nanorod CeO 2 (CeO 2 -R) and the corresponding Au/CeO 2 catalysts in HCHO oxidation. Reactivity tests showed that Au/CeO 2 -R is highly efficient and stable in HCHO oxidation at room temperature, which is attributed to the highly active Au-CeO 2 -R interface. The strong interaction between Au and CeO 2 -R greatly promotes the creation of oxygen vacancies and Au 3+ near the interface, which promotes the formation of formate. The conversion of formate can follow both a decomposition and a direct oxidation pathway, which is remarkably enhanced by the coexistence of Au 3+ and oxygen vacancies. In addition, formate accumulation and Au particles aggregation led to deactivation. The presence of humidity promotes the oxidation of formate, which improves the reactivity and stability of Au/CeO 2 in HCHO oxidation.
研究领域:
催化化学
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材料科学
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DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2019
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IF 8.355
Fenglei Liu,Guilong Peng,Tong Li,Gang Yu,Shubo Deng
A novel bio-adsorbent (DACS-TA) was synthesized via a facile crosslinking reaction between tannin acid (TA) and dialdehyde corn starch (DACS), and the adsorption behavior of Au(III) from aqueous solution onto the DACS-TA was evaluated in batch adsorption experiments. Fourier Transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopies were used to verify the successful crosslinking reaction, and the surface functional groups and the thermal stability of the prepared DACS-TA were also characterized. Adsorption results showed that the DACS-TA exhibited high adsorption capacity and selectivity towards Au(III), and the maximum adsorption capacity could reach up to 298.5 mg/g at pH 2.0 according to the Langmuir fitting. The adsorption isotherms of Au(III) on the DACS-TA were described well by the Langmuir model, indicating that the monolayer adsorption of Au(III) possibly occurred on the adsorbent surfaces. The kinetic data were fitted better by the Pseudo-second-order kinetic equation in comparison with the Pseudo-first-order and Intraparticle diffusion equations. Based on the SEM, XRD and XPS analysis, the adsorption-reduction mechanism of Au(III) on the DACS-TA was proposed. Namely, Au(III) was first adsorbed on the adsorbent and then was reduced to Au(0) while the phenolic group of TA was oxidized to carbonyl groups.
研究领域:
环境科学
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材料科学
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化学工程
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产品关联
DOI
高影响因子
Journal of Environmental Chemical Engineering
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2017
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IF 0
Quan Wang,Tuo Li,Pengfei Xie,Jiahai Ma
In this study, the interface effects of Cu 2 O and Au/Cu 2 O semiconductors were improved by addition of a magnesia (MgO) interface nanolayer (MIN) deposited via precipitation. The morphologies, crystal structures, chemical compositions, elemental states and optical properties of MgO/Cu 2 O and Au/MgO/Cu 2 O heterojunctions were characterized via SEM, XRD, XPS, UV–VIS–NIR and PL. It was found that the MIN has a surface passivation effect that inhibits the aggregation and oxidation of Cu 2 O. This enhances Cu 2 O semiconductors’ wettability and stability, improves crystallinity and reduces Au particle sizes. More importantly, the MIN promotes charge transfer via tunneling through the insulator, and enhances adsorption of molecular oxygen, facilitating superoxide radicals formation during photoreactivity. MgO/Cu 2 O and Au/MgO/Cu 2 O exhibited superior photodegradation of methyl orange, attributed to the boost of O 2 − and h + . This work confirmed the importance of MIN as a useful modification of semiconductor photocatalysts, and the MIN can significantly enhance the production of superoxide radicals in the photocatalytic activity with visible light.
研究领域:
材料科学
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环境科学
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化学
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产品关联
DOI
Colloid and Interface Science Communications
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2022
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IF 5.633
Zhiguo Zhang,Zilong Guo,Wensheng Yang
Coating silica on Au particles has been known to be effective to improve their stability and performance. In this work, we demonstrated a cetyltrimethylammonium bromide (CTAB) assisted approach for preparation of Au@SiO 2 particles in ethanol/water mixtures. At ethanol content of 0.25, Au particles were well dispersed, while at ethanol content of 0.50, the aggregated Au particles were gradually dispersed with increasing CTAB concentration, attributed to the gradual formation of CTAB bilayer on the particle surface. When tetraethyl orthosilicate and ammonia were added directly to the Au particle dispersions, the Au@SiO 2 particles formed at the low ethanol content (0.25) were red in color and spherical in shape with a core composed of single Au particles, and these formed at the medium ethanol content (0.50) were purple in color and fractal-like in shape with a core composed of multiple Au particles.
研究领域:
材料科学
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纳米技术
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DOI
高影响因子
CHEMICAL PHYSICS LETTERS
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2017
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IF 1.815
W.S. Huo,H. Zeng,Y. Yang,Y.H. Zhang
Enzymatic electrodes over-coated by thin film of nano-composite made up of polymer and functionalized nano-gold particle was prepared. Glucose/O 2 membrane-free enzymatic fuel cell based on nano-composite based electrodes with incorporated glucose oxidase and laccase was assembled. This enzymatic fuel cell exhibited high energy out-put density even when applied in human serum. Catalytic cycle involved in enzymatic fuel cell was limited by oxidation of glucose occurred on bioanode resulting from impact of sophisticated interaction between active site in glucose oxidase and nano-gold particle on configuration of redox center of enzyme molecule which crippled catalytic efficiency of redox protein.
研究领域:
生物化学
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纳米生物学
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能源科学
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DOI
高影响因子
Journal of Inorganic and Organometallic Polymers and Materials
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2017
·Vol. 27
·期 5
·1162-1176
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IF 1.577
Zeng Han,Yang Yang,Zhao Shu Xian,Zhang Yu He
Abstract Dependences of structural parameters and operational conditions on enzymatic catalysis of substrates (glucose and oxygen) for basal electrodes over-coated by composite consisting of nano-gold particle and polymer, were investigated systematically by the means of electrochemistry and spectrometry. Rate constants of steps involved in the whole catalytic cycle were estimated under the same dimension and were compared to confirm the limiting factor in the whole catalytic cycle. Results from experiments indicated that nano-gold particle surface anchored with aromatic ring as conductive support played the important role in achieving direct electron transfer between cofactors in redox protein molecules and electrical wired matrix. Complexations between components of nano-composite and redox sites within incorporated enzyme molecules acted as the paradoxical role in promoting the catalytic efficiency in the long term. Electrochemical conversion of substrates into product was identified to be the rate limiting step in the whole catalytic cycle for both enzyme based electrodes. Other parameters such as enzyme loading amounts in matrix, size of nano-particle and proportion of component in nano-composite only posed impact on magnitude of catalytic effect rather than the mechanism of catalysis. Graphical Abstract Transformation of substrate into product was ascribed to the limiting step in the whole catalysis for enzyme-based electrodes which resulted from great impact of interactions between enzyme carrier and redox protein on configuration of cofactors in enzyme molecules and binding ability to substrate for proteins.
研究领域:
生物化学
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电化学
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产品关联
DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2017
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IF 3.154
Zhen Zhang,Nuanfei Zhu,Shuaibing Dong,Menglu Huang,Liuqing Yang,Xiangyang Wu,Zhenjiang Liu,Jiahao Jiang,Yanmin Zou
On the basis of H2O2-mediated growth of gold nanoparticle (AuNPs), a novel plasmonic enzyme-linked immunosorbent assay (pELISA) was developed with a polyclonal antibody for the ultrasensitive simultaneous naked-eye detection of tetrabromobisphenol A bis(2-hydroxyetyl) ether (TBBPA DHEE) and tetrabromobisphenol A mono(hydroxyethyl) ether (TBBPA MHEE), one of the major derivatives and byproducts of tetrabromobisphenol A (TBBPA), respectively. In this modified indirect competitive pELISA, glucose oxidase (GOx) played an important role leading to the growth of AuNPs through a reaction between GOx and glucose to produce hydrogen peroxide (H2O2). In addition, further signal amplification was achieved via a large number of GOx molecules, which were immobilized on silica nanoparticles carrying poly brushes (SiO2@PAA) to increase the enzyme load, and the whole complex was conjugated on the second antibody. Under the optimized conditions, 10–3 μg/L TBBPA DHEE can be distinguished via the observation of a colored solution, and the limit of detection (LOD) of the method using a microplate reader reaches 3.3 × 10–4 μg/L. In contrast, the sensitivity of the method was 3 orders of magnitude higher than that using conventional colorimetric ELISA with the same antibody. Furthermore, the proposed approach showed good repeatability and reliability after a recovery test fortified with a variety of targets was performed (recoveries, 78.00–102.79%; coefficient of variation (CV), 4.38–9.87%). To our knowledge, this is the first case in which pELISA was applied for the detection of small molecules via the production of H2O2 from GOx and glucose. The method will be widely used for the investigation of TBBPA DHEE and TBBPA MHEE in real environments.
研究领域:
环境科学
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分析化学
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生物医学
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产品关联
DOI
PubMed
高影响因子
Nanoscale
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2015
·Vol. 7
·期 39
·16381-16388
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IF 7.394
Yanni Chen,Yongwei Wang,Liqiang Liu,Xiaoling Wu,Liguang Xu,Hua Kuang,Aike Li,Chuanlai Xu
A novel gold immunochromatographic assay (GICA) based on anti-β-lactam receptors was innovatively developed that successfully allowed rapid and simultaneous detection of fifteen β-lactams in milk samples in 5–10 minutes. By replacing the antibodies used in traditional GICA with anti-β-lactam receptors, the difficulty in producing broad specific antibodies against β-lactams was overcome. Conjugates of ampicillin with BSA and goat anti-mouse immunoglobulin (IgG) were immobilized onto the test and control lines on the nitrocellulose membrane, respectively. Since goat anti-mouse IgG does not combine with receptors, negative serum from mice labelled with gold nanoparticles (GNP) was mixed with GNP-labelled receptors. Results were obtained within 20 min using a paper-based sensor. The utility of the assay was confirmed by the analysis of milk samples. The limits of detection (LOD) for amoxicillin, ampicillin, penicillin G, penicillin V, cloxacillin, dicloxacillin, nafcillin, oxacillin, cefaclor, ceftezole, cefotaxime, ceftiofur, cefoperazone, cefathiamidine, and cefepime were 0.25, 0.5, 0.5, 0.5, 1, 5, 5, 10, 25, 10, 100, 10, 5, 5, and 2 ng mL−1, respectively, which satisfies the maximum residue limits (MRL) set by the European Union (EU). In conclusion, our newly developed GICA-based anti-β-lactam receptor assay provides a rapid and effective method for one-site detection of multiple β-lactams in milk samples.
研究领域:
分析化学
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食品安全
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生物医学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2023
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IF 9.9
Lijun You,Baohua Zhong,Ci Huang,Jumei Li,Zhijuan Zheng,Yang Wang
Au coated magnetic polyphosphazene (MPCTP) composite particles ( [email protected] ) were fabricated with sensitive SERS activity. The MPCTP particles were generated by coating polyphosphazene on Fe 3 O 4 nanoparticles through precipitation polycondensation of hexachlorocyclotriphosphazene and phloroglucinol . [email protected] composite particles were obtained by deposition of Au nanoparticles on MPCTP by the reduction of HAuCl 4 . The size and the thickness of the Au shell can be controlled by varying the amount of HAuCl 4 . The magnetic core endowed the composite particles with good magnetic responsiveness, which allowed the analyte to be enriched and separated from the complex matrix, and significantly simplifying the sample pretreatment procedure. The SERS activity of [email protected] composite particles were evaluated by DTNB as model Raman reporter, and the limits of detection (LOD) of DTNB was 10 -8 mol/L. A high efficient SERS immunoassay system based on the [email protected] substrates for the detection of immunoproteins was developed. Human IgG and rabbit IgG were quantitatively determinated simultaneously by this immunoassay system. The quantitative determination of the immunoglobulin G (IgG) was achieved and the LOD of human IgG, rabbit IgG and the mixture of human IgG and rabbit IgG were as low as 10 fg/mL, 100 pg/mL and 1 ng/mL, respectively. The results showed that the [email protected] composite particles have broad application prospects as high performance SERS active substrates for immunoprotein analysis.
研究领域:
材料科学
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分析化学
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生物技术
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产品关联
DOI
PubMed
高影响因子
SENSORS
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2019
·Vol. 19
·期 3
·640
·
IF 3.031
Meng Li,Jing Wu,Haiping Su,Yan Tu,Yazhuo Shang,Yifan He,Honglai Liu
In this work, three different aqueous solutions containing imidazole-based ILs with different alkyl chain lengths ([Cnmim]Br,n= 2, 6, 12) were adopted as the medium for the synthesis of ionic liquid-polypyrrole (IL-PPy) composites. Herein, the ILs undertook the roles of the pyrrole solvent, the media for emulsion polymerization of PPy and PPy dopants, respectively. The electrochemical performances of the three IL-PPy composites on a glassy carbon electrode (GCE) were investigated by electrochemical experiments, which indicated that [C12mim]Br-PPy (C12-PPy) composites displayed better electrochemical performance due to their larger surface area and firmer immobilization on the GCE. Further, C12-PPy/GCE were decorated with Au microparticles by electrodeposition that can not only increase the conductivity, but also immobilize sufficient biomolecules on the electrode. Then, the obtained C12-PPy-Au/GCE with outstanding electrochemical performance was employed as a horseradish peroxidase (HRP) immobilization platform to fabricate a novel C12-PPy-Au-HRP/GCE biosensor for H2O2detection. The results showed that the prepared C12-PPy-Au-HRP/GCE biosensor exhibited high sensitivity, fast response, and a wide detection range as well as low detection limit towards H2O2. This work not only provides an outstanding biomolecule immobilization matrix for the fabrication of highly sensitive biosensors, but also advances the understanding of the roles of ILs in improving the electrochemical performance of biosensors.Keywords:ionic liquids (ILs);polypyrrole (PPy);gold particles;horseradish peroxidase (HRP);enzyme immobilization;hydrogen peroxide sensor
研究领域:
材料科学
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电化学
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生物传感器
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分析化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
TALANTA
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2022
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IF 6.556
Ming Li,Wenying Lu,Yuhao Mao,Xuchun Qiu,Daolin Du
It is desired and urgently needed to improve the sensitivity of immunochromatography assay (ICA) for hazardous chemicals. In this work, an enhanced ICA strip was established and evaluated for simultaneous, semi-quantitative and quantitative detection of ochratoxin A (OTA) and aflatoxin B 1 (AFB 1 ). The signal strategy based on gold growth on the surface of the E. coli K12 carrier was recommended, which was successfully self-assembled on the enhanced ICA with a double test line pattern. When used as a novel carrier, the E. coli K12 could provide a larger surface area, better biocompatibility and high loading capacity, which was of great help to improve the performance of the ICA. By the naked eye, the semi-quantitative limit of detection (semi-Q-LOD) reached 0.03 ng/mL for both OTA and AFB 1 (17-fold and 33-fold lower than the conventional ICA strip). By the digitized strip reader, the quantitative LODs (Q-LODs) were all identified as 0.01 ng/mL for two mycotoxins (10-fold improvement), with detection ranges of 0.01–0.5 ng/mL for OTA and 0.01–0.2 ng/mL for AFB 1 . Furthermore, the high reliability and applicability of the ICA were confirmed by its good correlation with liquid chromatography-tandem mass spectrometry (LC-MS/MS). The advantages of the improved sensitivity, high efficiency and cost savings had been reflected for the ICA. This study could provide an important reference method for the sensitive, simultaneous, rapid and on-site monitoring of multicomponent contaminants.
研究领域:
食品安全检测
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分析化学
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生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Science & Engineering C-Materials for Biological Applications
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2015
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IF 3.088
Shuang Xu,Yan Li,Zhenjie Chen,Cuilan Hou,Tong Chen,Zhigang Xu,Xiaoyu Zhang,Haixia Zhang
Mesoporous silica nanoparticles (MSNs) combining gold particles (MSNs–Au) were synthesized as nanocarriers for glutathione (GSH) and pH dual-sensitive intracellular controlled release of the anti-cancer drug doxorubicin (DOX). The MSNs were used as an adsorbent for DOX, and the ultra-small gold nanospheres (Au NPs) partly operated as gatekeepers to control the release of DOX from the pores of MSNs and as the driver of drug release in the presence of GSH due to the association between GSH and Au particles. Under different pH conditions, DOX release changed due to different levels of dissociation between the –SH group on the MSNs and the Au particles. The composition, morphology, and properties of the as-prepared composites were characterized by elemental analysis, fluorescence spectroscopy, Fourier transform infrared spectroscopy, transmission electron microscopy, nitrogen adsorption–desorption, thermal gravimetric and UV–visible spectroscopy. The in vitro release experiments showed that these smart nanocarriers effectively avoided drug leakage in the neutral media. Cytotoxicity and imaging studies also indicated that DOX-loaded Au-MSNs ( [email protected] –Au) had a significant inhibitory effect on the growth of Tca8113 cells and sustained the release rate of DOX
研究领域:
纳米技术
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癌症研究
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药物递送系统
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）