Study On Dynamic SERS Substrate Using Flexible And Stretchable Plasmonic Metafilm

Surface-enhanced Raman spectroscopy(SERS),as an analytical method with high sensitivity,high resolution,no interference of water,has been widely used in many areas such as chemistry,biology,polymer science,medicine and so on.The performance of SERS substrates is one of the keys to the SERS detection.At present,the SERS substrate mainly amplifies the Raman signal by the localized surface plasmon resonance(LSPR)coupling effect generated by the dense metal nanoparticle gaps(1-5nm).However,in the practicle detection,the molecule to be detetcted is difficult to get into the gaps between the nanoparticles due to sterical hinder or the wetting mode,resulting in limited effect of the SERS detection.In this essay,this problem was analyzed and improved.The highly stretchable SERS-active elastomer(SSAM)was prepared by using polydimethylsiloxane(PDMS)as carrier.SSAM can be used to control the gaps between nanoparticles by simply mechanical stretching because of its excellent stretchability and good SERS enhancement and reproducibility,thus realizing the engineering of dynamic SERS hotspots,allowing more analytical molecules to enter the nanoparticle gaps and enhancing the SERS detection signal.In addition,the SSAM is integrated into the filter-like device,and the dynamic SERS hotspots is extended to multiple directions by the amount of the analytical solution added to adjust its degree of expansion,so that the detection effect on small molecules like CV can be enhanced by more than 70%.It was applied to the detection of pyocyanin with a detection limit of 1 n M,which can be increased by three orders of magnitude compared to the cyclic voltammetry.