Study On Gold And Silver Core-shell Nanoparticals As SERS Substrate For Organic Dye Detection

In recent years,with the rapid development of science and technology and industry,human society has increasingly engaged in the invasion of natural resources.The organic pollutants in the environment might be enriched through the food chain and eventually endanger human health.The organic dyes are typical organic pollutants.It is necessary to conduct a rapid,sensitive and accurate detection of organic dyes.SERS is the abbreviation of Surface-enhanced Raman spectroscopy with high sensitivity and fast response rate and is suitable for on-site monitoring compared with traditional detection methods.It can provide new method for the detection of organic dyes in solution environments.In this thesis,gold-silver core-shell nanoparticles(Au@AgNPs)were synthesized by seed-mediated method.The Au@AgNPs were characterized by scanning electron microscopy,transmission electron microscopy and UV-visible spectroscopy.The nanoparticle has a square-like Ag shell with side length of about 30 nm and an Au spherical core with diameter 10nm.In this paper,three organic dyes malachite green,methyl orange and rhodamine 6G were detected with Au@AgNPs as SERS substrates.The detection limits were 5.48×10-7mol/L,9.17×10-7mol/L and 2.09×10-8mol/L,respectively.The linear relationships between rhodamine 6G concentration and peak intensity were established among the range of 0.1mg/L-2.0mg/L.R2 was up to 0.9899.In addition,the repeatability of Au@AgNPs as a substrate was evaluated.12 parallel samples were tested.RSD%of two peaks were 9.04%and 14.30%.It indicated the stability of Au@AgNPs as SERS substrate is fine.Therefore,this paper provides a valuable reference for the detection of organic dyes using Au@AgNPs as SERS substrate.