The Construction And Application In Sers Detection Of Gold Nanoparticles Monolayer Films

High quality of Surface-enhanced Raman spectroscopy(SERS)substrate often requires highly tailorable electromagnetic(EM)field generated at nanoparticles(NPs)surfaces by the regulation for the components,size,morphologies and selfassembling structure of NPs.However,most currently universal approaches are restricted to the single component and integrating these key factors into one system to achieve the theoretically maximum signal amplification is still challenging.In this paper,gold nanoparticles with integration of multiple signal amplification factors were prepared by changing the morphology,chemical composition and roughness of particles and self-assembled on the water-oil interface to form the monolayer films,which were used to construct SERS nanoplatform with high sensitivity and repeatability.Based on the construction and application of gold nanoparticle monolayer films,this paper is mainly carried out from the following works:1.The etched spiky Au@Ag NPs were designed by changing the morphology,composition and roughness of nanoparticles and self-assembled on the water-oil interface to form the monolayer films,which were used to construct SERS nanoplatform with high sensitivity and repeatability.The effects of the spikiness structure,thickness of the Ag shell and roughness on SERS signal and electromagnetic field intensity were researched and integrated into a SERS nanoplatform to achieve the maximum theoretical amplification effect.The platform exhibited a significant electromagnetic enhancement of five orders of magnitude.Finally,the integrated triple amplification SERS platform enabled the effective detection of diverse molecules in the fileds pesticide residues,environmental pollutants and medical health,and its detection limit was as low as 10-11 M,which laid a foundation for trace tracking analysis of multi-domain molecules.2.Highly pure gold nanotriangles(Au NTs)were synthesized by seed-mediated growth method.And a large area of two-dimensional monolayer film was formed by self-assembly at the oil-water interface to obtain patterned flexible polydimethylsiloxane(PDMS)gold nanoparticle substrate,which were grew asymmetricly to construct 2D Janus Au NTs monolayer films nanoplatform.The influence of nanoparticles and substrate structure on SERS signal was deeply studied,and the two factors were integrated into a SERS nanoplatform and applied to detection of dye molecules.The detection limit was as low as 10-12 M,which had potential application value for the detection of irregular sample surface.