Surface-enhanced Raman scattering substrate based on silver nanoparticle-deposited phospholipid multilayer

Surface enhanced Raman scattering (SERS) substrate was fabricated by directly depositing Ag onto a multilayer lipid membrane consisting of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) lipids. The Ag nanoparticles were spontaneously formed on the POPC membrane surface during deposition and using 4-mercaptopyridine as a probe molecule, significant SERS enhancement was observed on the Ag nanoparticle-deposited POPC membrane over the Ag nanoparticles without POPC. It was conjectured that the presence of the POPC molecules assisted in forming a monolayer coverage of the analyte molecules on the nanoparticle surface, hence bringing the adsorbate molecules in closer proximity with the metal surface.