| Recently, security issue, such as water security, food security and public security, has raised serious concerns for public security. The detection of security pollutants can provide beneficial basis of prevention, treatment and punishment for the relevant departments to reduce the loss. Many researchers are committed to the development of security pollutants detection method. Most of the detection method is based on the field sampling combined with laboratory testing model, which need take a few hours or even days. However, sudden security issue accidents frequently happened. Testing personnel arrived at the scene the first time to conduct rapid on-site detection analysis. So on-site detection analysis technology has become a research hotspot at home and abroad. Several portable instruments had been used in the analysis of the actual test, such as portable ultraviolet-visible absorption spectrometer, portable fluorescence spectrometer, portable infrared spectrum instrument, portable Raman spectrometer. A portable Raman spectrometer is a good candidate for on-site detection of explosives, due to its features of high cost-effective, rapid analytical speed and nondestructive detection. However, the spectral resolution is relatively low, which leads to a poor sensitivity.Surface enhanced Raman spectroscopy (SERS) has emerged as an alternative sensing technique due to its unique features, such as high sensitivity and generation of a unique spectroscopic fingerprint. The preparation of ideal SERS substrate is the key step in the practical application. With the development of nanoscience and nanotechnology and the requirement of increasing the modern detection, the type of SERS substrate is becoming more and more diversified. The on-site sensitive detection of security pollutants using SERS is still a challenging job.1. A disordered silver nanowires membrane for extraction and surface-enhanced Raman spectroscopy detectionSilver nanowires were largely prepared by a solvothermal polyol process, which have a certain aspect ratio, and enable easy loading onto the membrane substrate. In this chapter, we reported the facile fabrication of a disordered silver nanowires extraction membrane by simply filtering method. The assembled silver nanowires with a 3D multilayered configuration brought about a strong EM enhancement effect and detected simply by swabbing the surface of detection area. Also, organic nitro-explosives, such as picric acid (PA) and 2,4-dinitrophenol (2,4-DNP), can also be detected sensitively. In addition, the simulated typical inorganic explosives such as black powders, firecrackers and match head could be detected.3. A electrochemistry treating silver nanowire membrane for sensitive surface enhanced Raman spectroscopy detectionElectrochemical oxidation/reduction cycles (ORCs) is a simple method for roughening the noble metal substrate to increase its SERS effect. A better sensitive surface enhanced Raman scattering (SERS)-active silver nanowire membrane has been developed by using the electrochemical oxidation/reduction cycles (ORCs) to roughen the silver nanowire membrane. Firstly, different conditions, such as scan rate and scan cycles, for electrochemically roughening silver nanowire membrane were investigated to obtain the best surface-enhanced Raman scattering (SERS) performance. P-aminothiophenol (PATP) was then used as a Raman probe to examine the effects of the preparation method on the intensity and stability of the SERS performance. We further studied the changes of the morphologies and structures by SEM, EDS, XRD. The electrochemistry treating silver nanowire membrane has good SERS-active and temporal stability under continuous laser irradiation. The inorganic ions (perchlorate) and organic pollutant (fluoranthene) can be detected by further modification. |
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