The Preparation Of Surface-enhanced Raman Scattering Active-substrate And Its Application In The Detection Of Pigment

Surface-enhanced Raman scattering(SERS)is a molecular vibration spectrum that has been widely applied in various fields.In this thesis,three kinds of SERS active-substrates of gold nanoparticles were prepared,optimized,characterized,and used to detect the artificial pigments.This thesis is divided into four chapters to elaborate:In the first chapter,the mechanism,the feature and the disadvantage of SERS were introduced in detail.Meanwhile,the preparation methods of SERS substrates and their application in various fields were summarized.Finally,the content of the dissertation was outlined.In the chapter two,the SERS active-substrate of gold nanoparticles was prepared by self-assembly method,which connected nanoparticles to form a well-organized gold nanoparticle layer through electrostatic adsorption.The enhancement effect of the SERS active-substrate was improved prominently.The enhancement homogeneity and stability of the as-prepared SERS active-substrate were investigated in the paper.Besides,it was applied to detect chrysoidine Ⅱ by SERS.The calibration curves showed good linearity in the range of 0.001-0.5 mmol/L with correlation coefficient r=0.9902.The minimum detectable concentration of chrysoidine Ⅱ was 0.0005 mmol/L.In addition,the results of recovery experiment of chrysoidine Ⅱ in dried beancurd sticks showed that the recovery was 70-120%,and the relative standard deviations(RSD)were 12.5-14.8%.In the chapter three,a method of chemical assembly integrated with the electrochemical method of cyclic voltammetry(CV)has been proposed for the fabrication of SERS active-substrate of globular gold nanostructures.Then,the influence of deposition time was studied.The enhancement,homogeneity and stability of the as-prepared SERS active-substrate were investigated in the paper.Besides,it was applied to detect of Rhodamine B(RhB)by SERS.The calibration curves showed good linearity in the range of 0.0005-0.1 mmol/L with correlation coefficient r=0.9940.And the minimum detectable concentration was 0.0003 mmol/L.In the chapter four,the SERS active-substrate of flowerlike gold nanostructures was fabricated by a functional biopolyer-polydopamine which could strongly attach to gold metal combined with cyclic voltammetry(CV).Then,the influence of deposition time was studied.The enhancement,homogeneity and stability of the as-prepared SERS active-substrate were investigated in the paper.Besides,it was applied to detect RhB.The calibration curves showed good linearity in the range of 0.005-1 mmol/L with correlation coefficient r=0.9991.And the minimum detectable concentration was 0.002 mmol/L.