Engineering Natural Materials as Surface-Enhanced Raman Spectroscopy Substrates for In situ Molecular Sensing
ABSTRACT Surface-enhanced Raman spectroscopy (SERS) is a powerful analytical tool. However, its applications for in situ detection of target molecules presented on diverse material surfaces have been hindered by difficulties in rapid fabricating SERS-active substrates on the surfaces of these materials through a simple, low-cost, and portable approach. Here, we demonstrate our attempt to address this issue by developing a facile and versatile method capable of in situ generating silver nanoparticle film (SNF) on the hydrophobic (even superhydrophobic) or hydrophilic surfaces of natural materials in a simple, cheap, practical, and disposable manner. Taking advantage of the high SERS enhancement ability of the prepared SNF, the proposed strategy can be used for in situ inspecting herbicide and pesticide residues on vegetables, as well as the abuse of antiseptic in aquaculture industry. Therefore, it opens new avenues for advancing the application prospects of SERS technique in the fields of food safety, drug security, as well as environment monitoring.
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ABSTRACT: Surface-enhanced Raman scattering (SERS)-active optical fiber sensor combining the optical fiber waveguide with various SERS substrates has been a powerful analytical tool for in situ and long-distance SERS detections with high sensitivity. The design and modification of SERS-active sensing layer with high quality is one of important topics in the development of novel SERS-active optical fiber sensors. Here, we prepared a highly sensitive SERS-active optrode by in situ fabricating a three-dimensional porous structure on the optical fiber end through a photo-induced polymerization reaction, followed with the photochemical silver nanoparticles growth above the porous polymer material. The fabrication process is rapid (finished within one hour) and can be on line under light control. The porous structure supports vast silver nanoparticles, which allows for strong electromagnetic enhancement of SERS. Interestingly, the preparation of this SERS optrode and its utilization for SERS detections can all be carried out in a microfluidic chip. The qualitative and quantitative on-chip SERS sensing of organic pollutants and pesticides have been completed by this SERS optrode-integrated microfluidic chip and its high detection sensitivity makes it promising in the analysis of liquid systems.ACS Applied Materials & Interfaces 06/2014; 6(14). DOI:10.1021/am503881h · 5.90 Impact Factor
Comprehensive Reviews in Food Science and Food Safety 05/2014; 13(3). DOI:10.1111/1541-4337.12062 · 3.54 Impact Factor
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ABSTRACT: Poor reproducibility limits the wide uptake of low-cost surface enhanced Raman spectroscopy (SERS) substrates. This study reports a relatively low-cost and reproducible cellulose nanofibre (CNF) textured SERS substrate. Utilizing a layer of CNFs deposited onto glass slides, nanoscale roughness was achieved, which facilitated effective aggregation of gold nanoparticles (AuNPs) to form a novel CNF textured SERS substrate. This substrate meets the critical roughness requirements to control the distribution of AuNPs to provide ‘hot spots’ for SERS detection, offering significant signal enhancement. The reproducibility and accuracy of low-cost cellulosic SERS substrates were significantly improved on a model SERS molecule of 4-aminothiophenol.Colloids and Surfaces A Physicochemical and Engineering Aspects 03/2015; 468. DOI:10.1016/j.colsurfa.2014.12.056 · 2.35 Impact Factor