RSC Advances
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2018
·Vol. 8
·期 66
·37729-37734
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IF 2.936
Xiaofeng Lin,Wensheng Lin,Meijia Yang,Jiayao Chen,Dingshan Yu,Wei Hong,Xudong Chen
The chain reaction amplification mechanism (CRAM) has been extensively studied, but it has not been effectively developed at the molecular scale and still needs to consume amounts of monomers to show the macroscopic phenomenon needed for detection. Herein, rationally-designed silica-coated silver nanoparticles with acrylic acid-functionalization were used as a plasmonic nanosensor to realize highly sensitive and fast colorimetric glucose detection with less monomer consumption, which effectively integrated CRAM with the localized surface plasmon resonance effect, developing CRAM at the molecular scale. The glucose detection mechanism of the proposed sensor was based on free-radical polymerization by biocatalytic initiation, which would induce the aggregation of Ag NPs, leading to a decrease in the plasmon resonance intensity. As a result, the detection limit could reach 2.06 × 10−5 M, 10 times lower than that of a commercial glucose assay kit with a limit of 1.1 × 10−4 M. Moreover, FDTD simulation further confirmed that the intensity of the extinction gradually decreased with an increase in the degree of aggregation of Ag NPs. The approach could be used for high selectivity toward glucose detection and would be suitable for other practical applications of the detection of low concentrations of glucose.
研究领域:
生物化学
·
纳米医学
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DOI
PubMed
高影响因子
Journal of Materials Chemistry A
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2013
·Vol. 1
·期 42
·13128-13138
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IF 0
Juan Zhou,Feng Ren,Shaofeng Zhang,Wei Wu,Xiangheng Xiao,Ying Liu,Changzhong Jiang
Tailorable synthesis of plasmon enhanced catalysts with high solar-light harvesting and energy-conversion efficiency has attracted wide interest due to its scientific and technological importance. In this paper, novel SiO2–Ag–SiO2–TiO2 multi-shell photocatalysts with wide-spectral-response were systematically designed and controllably synthesized, where the SiO2 spheres were used as the cores, and the SiO2 interlayers coated on the Ag nanoparticle (NP) shells were used to separate the Ag from the TiO2 shell. The structures of the SiO2–Ag–SiO2–TiO2 multi-shell photocatalysts can be tailored by changing the thickness of SiO2 interlayers from 1 to 2, 5, 8, 12, and 20 nm, while the anatase N-doped TiO2 shells with visible light response are maintained at a thickness of 20 nm. The photocatalytic activity tests show that the enhanced photocatalytic efficiency under both ultraviolet (UV) and visible light irradiation is related to the existence of Ag NP shells and the thickness of SiO2 interlayers. The complicated coupling mechanisms between TiO2 and a plasmon are systematically discussed, and a clear physical picture for the complicated coupling processes is presented. The main reasons for the enhancement of the photocatalytic activity of the SiO2–Ag–SiO2–TiO2 multi-shell structures are the localized surface plasmon resonance (LSPR) effect and scattering effect induced by Ag NPs.
研究领域:
材料科学
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光催化技术
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纳米科技
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DOI
JOURNAL OF CHEMICAL TECHNOLOGY AND BIOTECHNOLOGY
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2016
·Vol. 92
·期 3
·562-572
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IF 2.738
Yang Pan,Zongxue Yu,Heng Shi,Qi Chen,Guangyong Zeng,Haihui Di,Xiaoqing Ren,Yi He
BACKGROUND Membrane fouling is a main obstacle hindering wider application of membrane technologies, and can cause a decline in flux and increased energy consumption, and more frequent chemical or membrane replacement can increase the operating costs. Membrane fouling is mainly governed by organic fouling and biofouling. In recent years, the development of new materials has provided new methods and thoughts for the research and development of antifouling and antibacterial membranes. RESULTS In this study, to obtain both a highly hydrophilic, antifouling and antibacterial poly(vinylidene fluoride) (PVDF) membrane, in situ formed silver (Ag) nanoparticles were immobilized with silica (SiO 2 ) nanoparticles, and then chemically bound onto a PVDF ultrafiltration (UF) membrane surface. The surface modification processes were achieved through a remarkably facile and effective dip-coating method. The impacts of Ag/SiO 2 nanocomposites on membrane performance were investigated when applied in membrane filtration processes simultaneously. This membrane showed higher hydrophilicity and water permeation flux. The PVDF membrane exhibited antibacterial properties and displayed better anti-fouling performance. CONCLUSION The superior performance of the Ag/SiO 2 -PVDF membranes and this facile, effective and scalable modification method hold great promise for their practical application. This work would also be helpful for developing new antifouling and antibacterial membrane and related materials via a convenient and large-scale method. © 2016 Society of Chemical Industry
研究领域:
材料科学
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环境工程
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生物医学
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DOI
高影响因子
BIOMATERIALS
·
2018
·
IF 8.806
Qiong Wu,Jie Yu,Mei Li,Longfei Tan,Xiangling Ren,Changhui Fu,Zengzhen Chen,Feng Cao,Jun Ren,Laifeng Li,Ping Liang,Yu Zhang,Xianwei Meng
Usually the tumor thermal therapy is accompanied with inflammatory reactions, which in turn promote tumor growth and metastasis meanwhile. Herein, we prepared novel trifunctional PEG-IL/ZrO 2 -Ag@SiO 2 nanorattles, which can be used for CT imaging-guided simultaneous tumor microwave thermal therapy and resistance to bacterial infection. Under the microwave irradiation, the nanorattles present excellent microwave thermal properties. Simultaneously, the nanorattles have good antibacterial effect in vitro and in vivo, which can restrain bacterial growth effectively and reduce inflammation response during the microwave thermal therapy. In addition, the nanorattles also have the function of CT imaging, which can monitor the tumor therapy in real time. The strategy of simultaneous microwave thermal therapy and inflammation management effectively inhibits tumor growth in mice with a good anti-tumor effect (96.4%). This proof-of-concept investigation provides a simple and reliable strategy for tumor treatment and inhibiting inflammatory reaction using a multifunctional nanomaterial , indicating the great application prospect in tumor treatment by simultaneous eradicating tumor tissue and managing inflammation.
研究领域:
纳米技术
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癌症治疗
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医学成像
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热疗
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炎症管理
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抗菌材料
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产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY
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2020
·
IF 1.431
Emily C. Cheshari,Xiaohui Ren,Xin Li
Carbendazim is widely used in agriculture with resultant residues persisting in the environment posing a major concern to human and animal reproductive health. The focus of this study is to develop a stable and highly selective substrate for rapid, sensitive and cost-effective detection of carbendazim residues. A surface-enhanced Raman spectroscopy (SERS) active core–shell substrate was successfully prepared using molecular imprinting technology. Silver nanoparticles were prepared and coated with a thin silica (SiO2) shell to enhance the substrates' stability and recyclability. Subsequently, molecular imprinting on the Ag@SiO2 by precipitation polymerisation using carbendazim as the template was to ensure selectivity of the substrate. The composite Ag@SiO2-molecularly imprinted polymers(MIP) could selectively rebind and successfully detect carbendazim by SERS at concentrations as low as 10−9 M. The intensity of the Raman peaks increased with increase in the concentration of carbendazim. In addition, the substrate demonstrated reasonable reproducibility and reusability. The detection of carbendazim can be attributed to the presence of carbendazim-specific cavities on the imprinted shell to allow the analyte get onto or near the plasmonic core allowing electromagnetic and chemical enhancement resulting in the SERS signal. Therefore, Ag@SiO2-MIP is a stable and selective SERS substrate for detection of carbendazim.
研究领域:
分析化学
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环境科学
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材料科学
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农业科学
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产品关联
DOI
高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Zuwei Luo,Yun Shen,Di Fang,Chuanchao He,Yueqiang Cao,Wei Li,Yi-An Zhu,Jinghong Zhou,Xinggui Zhou
Support materials play vital roles in heterogenous catalysis via the so-called support effects, and understanding on the support effects is beneficial for the design of high-performance catalysts. Herein, we represent detailed investigations on the support effects of Ag catalysts for dimethyl glycolate (DMO) semi-hydrogenation to methyl glycolate (MG), where G6 silica with amorphous mesopores, SBA-15 with parallel mesopores and silica nanospheres (MSNS) with center-radial ones were employed as the supports. The hydrogenation activity decreases in the order of Ag/MSNS > Ag/SBA-15 > Ag/G6 while the MG selectivity in the order of Ag/G6 > Ag/MSNS > Ag/SBA-15 at the same reaction conditions, indicating remarkable support effects on both activity and selectivity. Structural characterizations, temperature programmed experiments and in-situ FTIR of DMO adsorption experiments demonstrate that the weak confinement effect of G6 leads to the larger sized Ag nanoparticles and weakened activation of DMO and H 2 , which contributes to low hydrogenation activity. In contrast, the ordered mesoporous SBA-15 and MSNS deliver well confinement effects for Ag nanoparticles and the activation of DMO and H 2 , but the distinct pore structures result in different activation and diffusion behaviors. Finally, DMO conversion and MG yield are well correlated with the competitive adsorption of H 2 versus DMO on Ag catalysts, indicating such competitivity as a descriptor for DMO semi-hydrogenation over Ag catalysts.
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
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2015
·Vol. 40
·期 14
·4777-4785
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IF 3.313
Jianmin Chen,Zhang-Hui Lu,Yuqing Wang,Xiangshu Chen,Lei Zhang
In this paper, we reported a facile and effective approach for fabrication of SiO 2 –CoFe 2 O 4 supported dispersed Ag nanoparticles (NPs). The as-synthesized nanocomposites (NCs) were characterized by XRD , TEM, EDX, ICP , XPS and N 2 adsorption-desorption, and used as catalyst for H 2 production from hydrolysis of ammonia borane (AB). A poorly active catalyst of Ag NPs was dramatically converted into a highly active catalyst, in the presence of inactive SiO 2 –CoFe 2 O 4 support. Among all the Ag(0)/SiO 2 –CoFe 2 O 4 NCs catalysts tested, the Ag loading of 0.98 wt% exhibited the highest catalytic activity toward hydrolysis of AB with a highly turnover frequency of TOF = 264 min −1 at room temperature, being higher than that of most reported Ag-based catalysts. Especially, these catalysts can be readily separated from the solution for recycle purpose, and can keep the high activity even after seven times of recycle. These results showed that Ag(0)/SiO 2 –CoFe 2 O 4 NCs prepared in this study are a promising catalyst for hydrogen production from aqueous AB and for developing a highly efficient hydrogen storage system for fuel cell applications .
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DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Yinhe Hai,Tong Guan,Yibin Feng,Ziheng Zhen,Youwei Yang,Ying Hu,Jing Lv,Yue Wang,Xinbin Ma
A promising route for producing biodegradable polyglycolic acid material from syngas has garnered increasing attentions. In this route, one of the pivotal issues is developing favorable catalysts for semi-hydrogenation of dimethyl oxalate (DMO) to methyl glycolate (MG). Silver catalysts were reported to be effective but suffered from the high cost. Herein, we prepared small-sized Cu@Ag/SiO 2 catalysts with appropriate Ag/Cu ratios by a facile wet impregnation method. This core–shell structure facilitated the intermetallic electronic transference from Cu to Ag. The surface exposure of electron-rich silver species could promote the catalytic activity and MG desorption in the DMO hydrogenation, which achieved high efficiency without compromising the MG selectivity. The optimal catalyst with Ag/Cu mass ratio of 3/2 displayed excellent space time yield towards MG of 47.3 g·g Ag −1 ·h −1 . These insights could offer a potential strategy to reduce the silver-based catalyst cost for the semi-hydrogenation of DMO to MG.
研究领域:
催化化学
·
材料科学
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产品关联
DOI
高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Menghan Guo,Jie Ding,Guojing Ji,Tian Xie,Huiwen Pang,Xiang Li,Qin Zhong
Ethyl glycolate (EGly) is a platform molecule in various fields, which has been widely applied for the production of various valuable chemicals. Despite being a traditional catalyst for the conversion of diethyl oxalate (DEO) to EGly, Ag/SiO 2 catalyst exhibits insufficient activity. The present study introduces a novel preparation method that couples H 2 O 2 reduction with deposition precipitation to augment the performance of the catalyst. Performance results show that Ag/SiO 2 catalyst prepared by the new method attains a DEO conversion of 95.6% and an EGly selectivity of 78.0%, showing respective improvements of 10.0 and 15.2% over excess impregnation-evaporating solvent method. Characterization results show that the average silver particles size of Ag/SiO 2 catalyst prepared by the new method is 6 nm, which is 1/2 of the excess impregnation-evaporation solvent method. Simultaneously, it contains a greater quantity of Ag 0 . The smaller and more uniform particles offer greater active site density, leading to enhanced DEO conversion. An increased presence of Ag 0 diminishes DEO overactivation and inhibits the dissociative adsorption of H 2 . Moreover, the amplified quantity of Ag 0 could be attributed to the reduced interfacial charge transport triggered by metal-support interactions (MSIs).
研究领域:
催化化学
·
材料科学
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产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2024
·
IF 4.1
Zhuoshi Li,Yinhe Hai,Yibin Feng,Tong Guan,Tiantian Xiao,Jing Lv,Shouying Huang,Yue Wang,Xinbin Ma
Methyl glycolate (MG) is an important building block for synthesizing biodegradable material of polyglycolic acid. Hydrogenation of coal-based dimethyl oxalate (DMO) to MG is quite promising, where Ag-based catalysts exhibited excellent selectivity. Here, a series of Ag/SiO 2 -x catalysts with particle sizes of 1.4–13.5 nm were prepared, which showed significant structural sensitivity in DMO hydrogenation. For Ag nanoparticles of 1.4–2.7 nm, the turnover frequency (TOF) was linearly increased with the surface electron density of silver, but when the Ag nanoparticles further enlarged, no significant variation of TOF was observed. Combining DFT calculation and experimental results of the model catalyst, triangular nanoplate, it was deduced that the Ag (1 1 1) played a dominant role in DMO hydrogenation to MG, originating from the benefited MG desorption as well as promoted dissociation of H 2 and DMO. This understanding about Ag particle size effect may provide guidance for designing efficient catalysts for DMO hydrogenation to MG.
研究领域:
催化化学
·
材料科学
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产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2019
·Vol. 7
·期 27
·8432-8441
·
IF 6.641
Jing Zhao,Chen Wu,Lipeng Zhai,Xiaofeng Shi,Xin Li,Guojun Weng,Jian Zhu,Jianjun Li,Jun-Wu Zhao
A surface-enhanced Raman scattering (SERS)-based sandwich type immunoassay was developed for the detection of α-fetoprotein (AFP) with high sensitivity, reproducibility and selectivity. In the immunoassay, an antibody immobilized nitrocellulose (NC) membrane was employed to capture AFP and antibody conjugated silica coated gold/silver core–shell nanostars (AuNS@Ag@SiO2) were used as SERS probes. AuNS@Ag was synthesized by the direct deposition of Ag on the AuNS. The Ag shell grew outward from the center towards the tips and adopted a polyhedral shape. The AuNS@Ag nanoparticles were shown to have higher SERS activity than gold nanostars (AuNSs), and their LSPR wavelengths could be finely tuned across a wide spectrum ranging from visible to near-infrared by simply adjusting the Ag shell thickness. The silica coating improved colloidal stability of the nanostructure and provided functionality for antibody conjugation. By using 4-mercaptobenzoic acid (4-MBA) as a Raman reporter molecule, the proposed SERS sensor is able to detect AFP with a low limit of detection (LOD) of 0.72 pg mL−1 and a wide and clinically relevant linear detection range from 3 pg mL−1 to 3 μg mL−1. Hence, this SERS-based immunoassay provides a strategy for the detection of trace AFP and has potential to assist in the monitoring of prognosis for hepatocellular carcinoma (HCC) patients.
研究领域:
分析化学
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纳米技术
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癌症研究
·
生物传感器
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产品关联
DOI
高影响因子
APPLIED PHYSICS LETTERS
·
2012
·Vol. 101
·期 1
·
IF 3.844
Zhou Yongcun,Wang Lu,Zhang Hu,Bai Yuanyuan,Niu Yujuan,Wang Hong
A kind of polymer based composites was prepared by embedding the fillers of core-shell Ag@SiO 2 nanoparticles into the polyimide (PI) matrix. The obtained Ag@SiO 2 /PI (50% vf of fillers) composites show remarkably improved high thermal conductivity and low relative permittivity. The maximum value of the thermal conductivity of composites is 7.88 W/(mK) and the relative permittivity and dielectric loss are about 11.7 and 0.015 at 1 MHz, respectively. Compared with self-passivated nanometer Al* particles composites, core-shell Ag@SiO 2 nano-composite is beneficial to increase the thermal conductivity and reduce the permittivity of the composites. The relative mechanism was studied and discussed.
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DOI
高影响因子
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