Surface Plasmon Catalysis And Spectroscopic Analysis Of 4-amino Diphenyl Disulfide

The rapid development of laser and computer technology has provided conditions for the advance and application of surface-enhanced Raman spectroscopy?SERS?technology.A large number of surface plasmons generated under the condition of SERS can greatly enhance Raman signals.Recent studies have shown that SERS technology is not just a non-destructive measurement technique,but something that can also stimulate chemical reactions.The time-resolved monitoring of the surface plasmon-assisted catalytic process can be performed in situ by Raman spectroscopy,which is of great significance to the study of surface plasmon-assisted catalysis.Raman spectra of 4-aminodiphenyl disulfide?APDS?were measured under different experimental conditions.In order to study whether surface plasmon-assisted catalytic reactions occur for different types and positions of surface plasmons for APDS.Spectroscopically,the surface plasmon-assisted catalytic reaction of APDS can be characterized,and the chemical mechanism of surface plasmon-assisted catalytic reaction was explored and studied.The article has studied the Raman spectra of APDS on the liquid,solid and silver foil surfaces and developed a new type of visual SERS detection technology has been developed.Based on the SERS response under solid phase conditions.The analyte is used as the substrate and the Ag nanoparticle is the detection probe.Besides the APDS coated with nano-silver particles and the APDS on the surface of the silver foil were measured by the mapping technique,and corresponding optical calculation images were obtained.What is more,the article has also done some reseach on the influence of the intermolecular distance on the surface plasmon-assisted catalytic reaction,according to the characteristic that can produce PATP-Ag.Further more,molecular and molecular vibrational modes of APDS and azobenzene?DMAB?are calculated by Gaussian 09 and provide data for theoretical studies.The results of the study have shown that:DMAB can be produced from PATP by surface plasmon-assisted catalytic reaction under SERS conditions,no matter it is under the liquid or solid environment.The newly developed solid-phase SERS detection technology,based on the analyte and the Ag nanoparticle is a detection probe,which can quickly realize the detection of the analyte distribution,and realize the visualization of the analysis and detection while obtaining the SERS spectrum.Raman spectroscopy and mapping results have demonstrated that for the same concentration of PATP and APDS,APDS forms a pair of closely spaced PATP-Ag on the surface of silver foil,and APDS has a higher conversion rate than PATP under the same experimental conditions.That is,for a lower concentration of the reaction system,the distance between molecules plays an important role in the efficiency of the coupling reaction.Local Surface Plasmon are generated on nanosilver particles,and Surface Plasmon Polariton are generated on the surface of the silver foil when irradiated with laser light.The surface plasmon-assisted catalytic reaction of APDS occurs to generate DMAB,whether Local Surface Plasmon or Surface Plasmon Polariton surface plasmon polaritons exist.The chemical reaction mechanism of APDS under SERS conditions is as follows:First,the S-S bond breaks,forming two closely spaced PATP-Ag.With the help of surface plasmons,NH₂ in PATP-Ag forms NH²⁺cation free radicals by losing electrons,and O₂ gets electrons that NH₂ loses with the existence of O₂.Then the two-NH₂⁺formed subsequently undergo a deprotonation reaction to form an Ar-NH-NH-Ar dimer.This dimer produces a new compound DMAB through a further deprotonation reaction.