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51.
Gold Nanoparticles Confined in Vertically Aligned Silica Nanochannels and Their Electrocatalytic Activity Toward Ascorbic Acid 下载免费PDF全文
Longhua Ding Wanzhen Li Qinqin Sun Yayun He Prof. Bin Su 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(40):12777-12780
A facile method of confining gold nanoparticles (AuNPs) in silica nanochannels aligned perpendicularly to an underlying electrode surface is reported. The nanochannel surface carrying a layer of (3‐aminopropyl)triethoxy silane (APTS) displays a strong electrostatic interaction with AuCl4?, eventually resulting in the confinement of AuNPs inside the nanochannels after chemical reduction. As‐prepared AuNPs in APTS‐modified mesoporous silica film (APTS‐MSF) are highly dispersed with a narrow size distribution. Furthermore, these AuNPs are free of protecting ligands and exhibit a good electrochemical catalytic activity toward the oxidation of ascorbic acid. 相似文献
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A novel amperometric biosensor based on self-assembling glutamate dehydrogenase (GLDH) and poly(amidoamine) dendrimer-encapsulated platinum nanoparticles (Pt-PAMAM) onto multiwall carbon nanotubes (CNTs) has been developed for the determination of glutamate. The formation of the self-assembled (GLDH/Pt-PAMAM)n/CNTs construction was investigated by ζ-potential and high resolution transmission electron microscopy (HRTEM). The results indicated the uniform growth of the layer-by-layer nanostructures onto carboxyl-functionalized CNTs. The electrocatalytic property of the (GLDH/Pt-PAMAM)n/CNTs modified electrode to glutamate in presence of NAD+ (β-nicotinamide adenine dinucleotide, 0.1 mM) was investigated at a low overpotential 0.2 V by electrochemical measurements. The results showed it had series of attractive characteristics, such as a large determination range (0.2-250 μM), a short response time (within 3 s), a high sensitivity (433 μA/mM−1 cm2) and good stability (85% remains after 4 weeks). 相似文献
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采用热解吸-电晕放电电离技术结合离子迁移谱,研究建立了化妆品中5种禁用卡因类化合物的现场快速筛查方法。化妆品样品无需前处理步骤,样品轻轻蘸取、滴加或喷雾在采样拭纸上,置于离子源样品槽中,采用热解吸-电晕放电电离技术实现样品中待测物的热解吸和离子化,随后以离子迁移谱进行快速筛查分析。5种卡因类化合物的检出限为10~50 ng,离子迁移谱分析时间小于20 ms,整个样品分析周期不超过1 min。本方法简便、快速、成本低廉,适用于化妆品中卡因类禁用组分的现场快速筛查。 相似文献
54.
We construct a quantum Ginsburg-Landau theory to study the quantum phase transition from the excitonic superfluid to a possible pseudospin density wave (PSDW) at some intermediate distances driven by the magnetoroton minimum collapsing at a finite wave vector. We explicitly show that the PSDW takes a square lattice structure. We suggest the existence of zero-point quantum fluctuation generated vacancies in the PSDW and that correlated hopping of vacancies in the active and passive layers in the PSDW state leads to very large and temperature dependent drag consistent with the experimental data. Comparisons with previous numerical calculations are made. Further experimental implications are given. 相似文献
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In this paper, an ultrasensitive CE-CL detection system coupled with a novel double-on-column coaxial flow detection interface was developed for the detection of PCR products. A reliable procedure based on this system had been demonstrated for qualitative and quantitative analysis of genetically modified organism-the detection of Roundup Ready Soy (RRS) samples was presented as an example. The promoter, terminator, function and two reference genes of RRS were amplified with multiplex PCR simultaneously. After that, the multiplex PCR products were labeled with acridinium ester at the 5'-terminal through an amino modification and then analyzed by the proposed CE-CL system. Reproducibility of analysis times and peak heights for the CE-CL analysis were determined to be better than 0.91 and 3.07% (RSD, n=15), respectively, for three consecutive days. It was shown that this method could accurately and qualitatively detect RRS standards and the simulative samples. The evaluation in terms of quantitative analysis of RRS provided by this new method was confirmed by comparing our assay results with those of the standard real-time quantitative PCR (RT-QPCR) using SYBR Green I dyes. The results showed a good coherence between the two methods. This approach demonstrated the possibility for accurate qualitative and quantitative detection of GM plants in a single run. 相似文献
56.
DNA‐Encoded Tuning of Geometric and Plasmonic Properties of Nanoparticles Growing from Gold Nanorod Seeds 下载免费PDF全文
Tingjie Song Dr. Longhua Tang Li Huey Tan Dr. Xiaojing Wang Nitya Sai Reddy Satyavolu Dr. Hang Xing Dr. Zidong Wang Prof. Jinghong Li Prof. Haojun Liang Prof. Yi Lu 《Angewandte Chemie (International ed. in English)》2015,54(28):8114-8118
Systematically controlling the morphology of nanoparticles, especially those growing from gold nanorod (AuNR) seeds, are underexplored; however, the AuNR and its related morphologies have shown promises in many applications. Herein we report the use of programmable DNA sequences to control AuNR overgrowth, resulting in gold nanoparticles varying from nanodumbbell to nanooctahedron, as well as shapes in between, with high yield and reproducibility. Kinetic studies revealed two representative pathways for the shape control evolving into distinct nanostructures. Furthermore, the geometric and plasmonic properties of the gold nanoparticles could be precisely controlled by adjusting the base compositions of DNA sequences or by introducing phosphorothioate modifications in the DNA. As a result, the surface plasmon resonance (SPR) peaks of the nanoparticles can be fine‐tuned in a wide range, from visible to second near‐infrared (NIR‐II) region beyond 1000 nm. 相似文献
57.
Internal Structure Tailoring in 3D Nanoplasmonic Metasurface for Surface-Enhanced Raman Spectroscopy
Tao Jiang Pratibha Goel Hui Zhao Rui Ma Linghua Zhu Xiangjiang Liu Longhua Tang 《Particle & Particle Systems Characterization》2020,37(1):1900345
Tunable nanoplasmonic metasurfaces have resulted in many versatile platforms for sensing applications including surface-enhanced Raman scattering (SERS)-based detection. However, to date, their fabrication still faces challenges in uniformity, repeatability, and controllability. Here, a novel large-area and hierarchical nanoplasmonic array with controlled internal structure and tunable plasmonic properties is reported, relying on controllably tailoring the single nanosphere on a uniform double-layered array into a well-defined nanoflower structure. The fabrication involves colloidal self-assembly, lithography, and plasmonic metal coating. First, a uniformly distributed double-layered colloidal array is fabricated via an ethanol-assisted self-assembly technique. Next, with the help of inductively coupled plasma dry etching, the lower layer is transformed to the nanoflower array with well-defined petal shape. Subsequently, a gold film with controlled thickness is deposited onto the nanoflower structured array, resulting in a tunable optical and SERS-active enhancement effect. Furthermore, 3D finite-difference time-domain simulation shows multiple enhancement sites inside the nanoflower array. Such a brand-new 3D structured array has the potential for varied applications, ranging from SERS sensors to light regulation. 相似文献
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Yue Lin Linlin Yang Guiyin Yue Lifen Chen Bin Qiu Longhua Guo Zhenyu Lin Guonan Chen 《Analytical and bioanalytical chemistry》2016,408(25):7105-7111
60.
The fluorescence lifetime based FRET distance measurements using sitespecific incorporated unnatural amino acid HC and Alexa488 as FRET pair revealed the different conformations of PYL10-CL2 upon ABA binding. 相似文献