排序方式: 共有11条查询结果,搜索用时 15 毫秒
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表面增强拉曼光谱对西地那非类药物的快速检测 总被引:3,自引:0,他引:3
采用表面增强拉曼光谱(SERS)技术并结合简单的前处理流程,对保健品样品中11种西地那非类药物进行了非定向快速筛查研究.结果表明,11种西地那非类药物可根据结构分为5类,类别之间SERS谱图差异显著;类别内SERS谱图具有共性特征,特征峰相对强度差异明显.实际样品的检测中,西地那非类药物的最低检出浓度约为0.05 mg/kg;前处理和测试的总时长约为3~5 min,且与检测目标物和样品无关.本方法高灵敏度、快速和非定向检测的设计理念为快速检测保健品中违禁添加药物提供了新思路和新方法. 相似文献
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Chen J Jiang J Gao X Liu G Shen G Yu R 《Chemistry (Weinheim an der Bergstrasse, Germany)》2008,14(27):8374-8382
The present study reports the proof of principle of a reagentless aptameric sensor based on surface-enhanced Raman scattering (SERS) spectroscopy with "signal-on" architecture using a model target of cocaine. This new aptameric sensor is based on the conformational change of the surface-tethered aptamer on a binding target that draws a certain Raman reporter in close proximity to the SERS substrate, thereby increasing the Raman scattering signal due to the local enhancement effect of SERS. To improve the response performance, the sensor is fabricated from a cocaine-templated mixed self-assembly of a 3'-terminal tetramethylrhodamine (TMR)-labeled DNA aptamer on a silver colloid film by means of an alkanethiol moiety at the 5' end. This immobilization strategy optimizes the orientation of the aptamer on the surface and facilitates the folding on the binding target. Under optimized assay conditions, one can determine cocaine at a concentration of 1 muM, which compares favorably with analogous aptameric sensors based on electrochemical and fluorescence techniques. The sensor can be readily regenerated by being washed with a buffer. These results suggest that the SERS-based transducer might create a new dimension for future development of aptameric sensors for sensitive determination in biochemical and biomedical studies. 相似文献
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护环柱面上受线性分布压力,端面上有不同的剪力和弯矩作用下的弹性解 总被引:1,自引:0,他引:1
对护环在柱面上受线性分布压力,并在两端面上有不同的剪力和弯矩作用的情况,应用一个新的位移函数,推出了弹性解. 相似文献
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Yan Long Xiang Chen Xiaoxin Pan Jinxia Duan Xiaoqing Li Yongcheng Wu Jie Tang Guokun Ma Liangping Shen Jun Zhang Hao Wang 《固体物理学:研究快报》2024,18(3):2300342
Neuromorphic devices are one of the promising electronic devices that are implementing artificial neural networks and substituting for traditional semiconductor devices in recent years. Inorganic halide perovskite (IMHP) is considered as an advantageous material to constitute neuromorphic components. Herein, the CsPbIBr2 memristor displays superior resistive-switching properties under various temperature and storage periods. In addition, synaptic plasticity, including paired pulse facilitation and spiking timing-dependent plasticity, is observed for CsPbIBr2 device, whose resistance manipulation is also established in both DC and pulse modes. Moreover, the decimal operation function of numbers by applying pulse stimulation to the device to regulate the device conductance is realized. This work demonstrates the feasibility of IMHP in neuromorphic devices, accelerating the application of neuromorphic computing. 相似文献
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By simply adding ascorbic acid in advance of AgNO3, the size and shape controllable Au/Ag bimetallic nanoparticles (NP) were prepared in the traditional Au growth solution free of seed at room temperature. The size distribution of NP is well uniform with ca. 10%–15% standard deviation in diameter. By changing CTAB concentration, the size and shape of NPs are tunable. After researching the surface‐enhanced Raman spectroscopy (SERS) behavior of the prepared NPs, an enhancement factor varied from 4.3×104 to 1.1×105 was obtained for the NP centered at ca. (64±8) nm. Electrochemical cyclic voltammetric results revealed that the so formed nanoparticles were Au riched Au/Ag bimetallic NP, and this formation might be due to the disproportionation reaction of Au+ prompted by Ag+ and the under potential deposition process of Ag+ on Au. 相似文献
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Surface-enhanced Raman spectroscopy (SERS) is a vibrational spectroscopy technique with sensitivity down to the single molecule level that provides fine molecular fingerprints, allowing for direct identification of target analytes. Extensive theoretical and experimental research, together with continuous development of nanotechnology, has significantly broadened the scope of SERS and made it a hot research field in chemistry, physics, materials, biomedicine, and so on. However, SERS has not been developed into a routine analytical technique, and continuous efforts have been made to address the problems preventing its real-world application. The present minireview focuses on analyzing current and potential strategies to tackle problems and realize the SERS performance necessary for translation to practical applications.Surface-enhanced Raman spectroscopy (SERS) is a vibrational spectroscopy technique with sensitivity down to the single molecule level that provides fine molecular fingerprints, allowing for direct identification of target analytes. 相似文献
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Reliable Quantitative SERS Analysis Facilitated by Core–Shell Nanoparticles with Embedded Internal Standards 下载免费PDF全文
Wei Shen Xuan Lin Prof. Chaoyang Jiang Chaoyu Li Haixin Lin Jingtao Huang Shuo Wang Dr. Guokun Liu Prof. Xiaomei Yan Prof. Qiling Zhong Prof. Bin Ren 《Angewandte Chemie (International ed. in English)》2015,54(25):7308-7312
Quantitative analysis is a great challenge in surface‐enhanced Raman scattering (SERS). Core‐molecule‐shell nanoparticles with two components in the molecular layer, a framework molecule to form the shell, and a probe molecule as a Raman internal standard, were rationally designed for quantitative SERS analysis. The signal of the embedded Raman probe provides effective feedback to correct the fluctuation of samples and measuring conditions. Meanwhile, target molecules with different affinities can be adsorbed onto the shell. The quantitative analysis of target molecules over a large concentration range has been demonstrated with a linear response of the relative SERS intensity versus the surface coverage, which has not been achieved by conventional SERS methods. 相似文献
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Chen P Zhou X Shen H Andoy NM Choudhary E Han KS Liu G Meng W 《Chemical Society reviews》2010,39(12):4560-4570
This tutorial review covers recent developments in using single-molecule fluorescence microscopy to study nanoscale catalysis. The single-molecule approach enables following catalytic and electrocatalytic reactions on nanocatalysts, including metal nanoparticles and carbon nanotubes, at single-reaction temporal resolution and nanometer spatial precision. Real-time, in situ, multiplexed measurements are readily achievable under ambient solution conditions. These studies provide unprecedented insights into catalytic mechanism, reactivity, selectivity, and dynamics in spite of the inhomogeneity and temporal variations of catalyst structures. Prospects, generality, and limitations of the single-molecule fluorescence approach for studying nanocatalysis are also discussed. 相似文献