Comparison of SERS activity of sputtered, electroless-plated and nanoparticle-coated plastic fiber optic probes

Surface Enhanced Raman Scattering (SERS) spectroscopy is a promising tool for trace molecule analysis. Substrate development plays a crucial role in determining the SERS signal enhancement and the analyte detection limits. In this study, Plastic fiber optic (POF, 0.75 mm fiber diameter) U-bent probes coated with plasmonic gold obtained by three different approaches, namely sputtering, electroless-plating and Au nanoflower (AuNF) chemisorption are compared for their SERS activity using thiophenol as a model Raman analyte. The minimally sputtered probes produced detectable analyte peaks at low power but with lower enhancement. Substrates with increased sputter deposition times provided better enhancement. However, the AuNF-coated probes gave maximum SERS enhancement even at low power.