Study Of Synthesise And Structural Control Of Ag Nanoparticles And Its SERS Application Research

SERS substrates play a vital role in SERS and the research on the SERS active substrates remains a hot topic. In this paper, two SERS active substrates are reviewed which were used in the detection of biological macromolecules and explosives molecular. Our study is outlined as follows:Firstly, three kinds of Ag nanoparticles were prepared by the chemical reduction method. Then got two types substrate, which the size and density are controllabled, from these Ag nanoparticles under changing experimental conditions. The SERS substrate is characterized by UV-vis absorption spectrometer, transmission eleetron microscopy, field emission scanning electron microscope and Raman spectrometer.We can roughly divide the our substrates into flexible suspended and rigid non-suspended ones according to their state in the detection. The flexible suspended substrate was a substrate that graphene oxide (GO) mediated SERS substrate supporting silver nanoparticles, which is characterized with the formation of stable suspension in the detection. Moreover the tight anchoring of silver nanoparticles on the platform by a multiple oxygen-containing groups on GO carbon grid favors for the generation of large number of "hot" spots. We demonstrate that anchoring of the4-mercaptopyridine (4-Mpy) analyte at these system leads to a pronounced intensification of its Raman emission using described SERS assay. Most impressively, acting as a new type of SERS substrate, the Substrate can disperse well in water during the detection process, which makes the Raman signals very uniform. This SERS substrate not only shows that target molecule such as4-Mpy has a strong interaction with the nanoparticle surface can be detected quickly and accurately with high sensitivity and stability, but also show SERS activity successfully for Bovine Serum Albumin (BSA), which interaction with nanoparticle surface is weak, in about physiological saline of Label-Free detection. Thus the substrate may apply in many fields such as biological situ detection system.The non-suspended ones is three layer structure that PDDA as a bridging agent between silver particles and glass plate like a sandwich. This SERS substrate showing good SERS activity in trace detection of explosives such as molecule RDX quickly and accurately with high sensitivity. We hope this substrate could play a role in the explosion detection on the scene of the accident site in the future.