The Influence Of Ions On Surface Plasmon Catalytic Reaction And SERS Analytical Method

Surface-enhanced Raman scattering（SERS）is a surface analysis method for the identification and validation of molecules structural information and it is based on the vibration of chemical bonds.The structure of the adsorbed substance could be well obtained based on the Raman probe absorbed on the metal nanoparticles.It is well known that the electromagnetic field effect of metal nanoparticles can amplify the SERS signals to obtain the accurate spectral signal.SERS spectroscopy could used for structure and quantitative analysis as it high sensitivity,easy operation and non-destructive and thus be used in a variety of chemical analysis.The detection of ion is more and more popular in various fields.In order to detect ions more conveniently and quickly,many analytical methods have been established.Based on the characteristic of high sensitivity with SERS spectroscopy,which is widely used in the fields of ions quantitative detection and surface plasmon-driven catalytic reaction.Therefore,this paper is based on the basic theory of surface-enhanced Raman spectroscopy technology,the combination of theory and experiment,especially for the influence of ions on surface plasmon-driven catalytic reaction and SERS analysis and detection.（1）Based on surface plasmon-driven catalytic reaction,especially for after the addition of Fe²⁺in 4,4’-dinitrodiphenyl disulfide（NPDS）to convert into 4,4’-dimercaptoazobenzene（DMAB）was investigated.This project discovered the new enhencement phenomenon of NPDS that the characteristic band of DMAB would be enhenced in SERS spectrum after the addition of Fe²⁺under acid solution.Combined with plasmon-driven catalytic and density functional theory,the mechanisms of Fe²⁺triggered surface plasmon-driven catalytic conversion of NPDS on AuNPs was studied.Based on the above Fe²⁺triggered reaction,a rapid analytical method based on surface plasmon-driven catalytic reaction of SERS chips.The results indicated that this method is suitable for the detection of Fe²⁺in real samples.（2）Based on surface-enhanced Raman spectroscopy and plasmon-driven catalytic theory,the influence of SERS spectrum after the addition of nitrite（NO₂^-）was investigated.It is found that the new band phenomenon of OATP that the characteristic band at 1323 cm^-1 will be appeared in SERS spectrum after the addition of NO₂^-in acid solution.Combined with the research of density functional theory and organic chemistry,it is confirmed that the change of SERS spectrum is due to the cyclization reaction of OATP convert to 1,2,3-Benzothiadiazole（BTA）.The reaction mechanism of this reaction was further studied and by exploring the effect of ambient conditions,the volume of sample and the reaction time on the conversion of OATP to BTA.The SERS analytical method based on plasmon-driven catalytic reaction of monitoring NO₂^-was established.