Characterization of Au and Ag nanoparticle coated silica nanosprings - Toward SERS based diagnostic applications

摘要

Silver (AgNP) and gold (AuNP) nanoparticle coated silica lanosprings (NS) are introduced herein as novel materials with high Surface Enhanced Raman Scattering (SERS) activity. Silica nanosprings were coated with nanoparticles using chemical vapor deposition or chemisorption of either pre-synthetized or in-situ synthesized nanoparticles. Controlled patterning of NPs on silica nanosprings resulted in small interparticle spacing and concomitant formation of SERS hot spots. Chemisorbed nanoparticles on nanosprings gave rise to significantly higher Raman enhancements than monolayers of chemisorbed nanoparticles on glass cover slips. Enhancement factors as high as 108 and 109 were obtained from AuNP (20 nm) and AgNP (35 nm) coated nanosprings, respectively.