Silver nanowires (AgNWs) growth in-situ on chitosan polymer matrix film for SERS application

Chitosan polymer matrix film is prepared from a mixed solution of chitosan and silver nitrate by drop-casting at different surfaces. The film shows various advantages for handling such as flexibility and mechanical strength. UV-Vis, FTIR, SEM and XRD analysis confirms the reduction of silver nitrate to form silver nanoparticles (AgNPs) and its in-situ growth of the silver nanowires (AgNWs) in the film. Surface-enhanced Raman spectroscopy (SERS) analysis demonstrates that the AgNWs/chitosan film displays a robust enhancement of the intrinsic Raman signals of chitosan, which serves as proof-of-concept that the chitosan-AgNW thin film will be unique for SERS verification with the advantage of avoiding the use of fluorophore tags and potentially being an easy-to-fabricate SERS substrate amenable for sensing application.