| Surface-enhanced Raman scattering(SERS)technology has the advantages of high sensitivity,simple sample preparation,and no interference in water systems.In recent years,with the continuous improvement of SERS technology,it has been widely used in food testing,environmental testing,petrochemicals,and other fields.The choice of a SERS-improved base affects the enhanced effect of the Raman signal to a great extent.The preparation of uniform,good stability,and strong enhanced SERS substrate has become a research hotspot in recent years.Thus,in this study,we used two preparation methods of SERS substrate to prepare precious metals and precious metal-semiconductor nanocomposite materials,and we conducted a detailed study on the enhanced effect and stability of the prepared SERS substrate.In the first part,a simple synthesis method was adopted to prepare gold nanoparticles as a SERS substrate.Under the condition of adding no other reducing agents and stabilizers,the nematic liquid crystal molecule,N-(4-methoxybenzyl)-4-butylaniline(MBBA),was used to synthesize gold nanoparticles for SERS active substrate in one step.Further,by adjusting the reaction temperature,reaction time,and other conditions to choose the best experimental conditions,the synthesized gold nanoparticles have excellent SERS-improved activity and good stability.Subsequently,the preparation method was used to grow gold nanoparticles in the capillary through capillarity,and the gold nanoparticles are used as a portable SERS substrate.The preparation method adopted in this work can provide a new direction for the preparation of SERS active substrate through further improvement.In the second part,Ag–ZnO nanocomposite was prepared as a SERS active substrate by combining hydrothermal growth and chemical reduction leaching method.Rhodamine 6G(R6G)probe molecule was used to explore the SERS activity of the substrate.The results showed that the SERS signal of the R6 G molecule was significantly enhanced,which was mainly because the substrate could realize the electromagnetic enhancement of metal nanoparticles and the chemical enhancement of semiconductor materials simultaneously.Using this substrate can also effectively promote the coupling reaction of p-aminophenol(PATP)to4,4 ′-dimercaptoazobenzene(DMAB)through charge transfer between Ag–ZnO molecules.This work shows that metal-semiconductor nanocomposites have great application potential in the selection and preparation of SERS active substrates. |
