Preparation Of Highly Sensitive SERS Optrode And Application

A surface-enhanced Raman scattering (SERS) technique is a high sensitive spectratechnique. Enormous signal enhancement permits an ultrahigh detection sensitivityfor analytes and extends SERS applications to broader fields, such as single moleculedetection, pesticide residue inspection, pharmacy, etc. Moreover, SERS is a powerfulanalytical tool with respect to fingerprint information, which makes it possible totrack analytes with individual identities in a complicated system. Many advantages ofSERS have attracted a great number of researchers in physical, chemical andbiological fields, and their efforts have been devoted to allowing the SERS techniqueto become an interdisciplinary subject. One of these attempts is to combine a SERStechnique with an optical waveguide to produce optically integrated devices. In thesedesigns, a SERS-active sensing layer usually consisting of metal nanoparticles or ametal film is required to fix on the optical elements. The optical waveguide playsmultiple roles in incident light guiding and Raman scattering light collection. One ofthe important optical waveguide components, the optical fiber, has many advantages,such as low signal loss and little external interference. The SERS optrode combiningthe optical fiber technique with the surface-enhanced technique could be used insample detection and obtain its information of structure. As well as, it can carry outthe lossless, in situ, on line, and remote sensing etc. The SERS optrode-integratedmicrofluidic system achieved the on-chip SERS analysis and detection, and it has animportant value in chemical and biological fields. 1、preparation a high sensitive SERS optrode by in situ photoinduced reactionsand its application.In this research, a SERS optrode was prepared by UV light photopolymerizationporous polymer on the end face of the optical fiber in situ, then the silvernanoparticles were deposited on the polymer by in situ photoinduced reactions. Thephotopolymerization time and the effect of the pore size impact on the SERS signalintensity have been exploration and discusses, as well as the poisonous starch maleicacid were tested in water solution, which obtained a good SERS effect. Thisexperiments also show that the method of the preparation of SERS optical fiber sensorhave simple preparation and high sensitivity of SERS.2、 A SERS optrode prepared by in situ photoinduced reactions and itsapplication for highly sensitive on-chip detection.Here, we prepared a highly sensitive SERS-active optrode by in situ fabrication of athree-dimensional porous structure on the optical fiber end via a photoinducedpolymerization reaction, followed by the growth of photochemical silvernanoparticles above the porous polymer material. The fabrication process is rapid(finished within1h) and can be on line under light control. The porous structuresupports vast silver nanoparticles, which allows for strong electromagneticenhancement of SERS. Interestingly, the preparation of this SERS optrode and itsutilization for SERS detection can all be conducted in a microfluidic chip. Thequalitative and quantitative on chip SERS sensing of organic pollutants and pesticideshas been achieved by this SERS optrode-integrated microfluidic chip, and its highdetection sensitivity makes it a promising factor in the analysis of liquid systems.