Study On The Catalytic Coupling Reaction Of -NH₂/-NO₂ Induced By Surface Plasmon Under SERS Monitoring

In recent years,with the research and development of Raman spectroscopy,surface-enhanced Raman scattering(SERS)has been applied in many fields such as petrochemical,biomedical testing and food safety.In the continuous development of science and technology,a large number of environmental pollution problems in chemical companies have been increasing.Among these environmental pollution problems,the types of organic pollution molecules account for the majority,especially aromatic compounds and organic dye molecules that are highly carcinogenic.These compounds are basically equipped with amino,mercapto,nitro and carboxy groups.Organic molecules with these groups can be adsorbed on rough metal surfaces and detected under SERS.The content of this dissertation is based on a series of studies based on SERS,using organic compounds with nitro or amino groups as probe molecules.The related work of this topic is mainly carried out from the following two aspects:(1)The first part of the work is to study the influence of the probe-based catalytic coupling reaction by changing the concentration of the probe molecules in the liquid phase,the pH of the solution,and the test conditions under SERS-based detection.The coupling reaction of the probe molecule with nitroaniline(PNA)was tested and analyzed.According to the SERS spectrum,the peak intensity ratio of the characteristic peak of the reaction was fitted to the pH value to obtain a good linear relationship;a linear mapping test was performed on the mixed solution of PNA and silver sol in the capillary to show the stability of the reaction.This part of the work is mainly to provide some theoretical basis for the detection of organic molecules in the case of adjusting the pH of the environment.(2)The second part of the research work is to use a different type of semiconductor silicon loaded with silver nanoparticles as the SERS substrate to provide a method for preparing a stable semiconductor metal composite SERS substrate.SERS detection of p-aminothiophenol(PATP)and p-nitrothiophenol(PNTP)using probe molecules induced by a typical surface plasmon,to study the mechanism of photo-induced charge transfer in semiconductor-metal-molecular systems;characterize semiconductor metal composite substrates using SEM,ICP,etc;characterization of the photocatalytic reaction of the probe molecules using Mappingand electrochemistry showed that light on different silicon substrates can affect the growth morphology of nanoparticles;at the same time,combined with the results of some corresponding theoretical calculations,it is shown that the electrons or holes generated by the P / N type semiconductor under laser induction can achieve a selective coupling reaction of driving molecules.