Gold nano-barcodes for molecular sensing platforms
W.-S. Chae, H.-O. Lee, J.-S. Jung
Korea Basic Science Institute, KR
Keywords: gold, nanobarcode, SERS, Raman imaging
Abstract:In this study, we fabricated uniquely structured barcode nanorods through simple templating route using porous alumina membrane as a host template. Novel metal components of gold and gold-silver alloy were alternatively electroplated in the cylindrical nanopores of the porous alumina template. Gold/porous gold (p-gold) multisegmented nano-barcodes were obtained by dissolving the oxide template out by HF and subsequent dealloying of silver phase by nitric acid. The resulting p-gold segment has two distinctive advantages for molecular sensing applications: Uptake of more probe molecules than that on smooth-gold segment due to high surface area, and electric field accumulation in the localized nanopores. The summation of the chemical and physical enhancement factors in the p-gold segment of the nano-barcodes presented relative enhancement of surface-enhanced Raman scattering compared to the near-by smooth-gold segments. Similarly, relative fluorescence quantum yield difference was also observed from fluorescence lifetime imaging studies for the adsorbed probe molecules on the novel metal nano-barcodes. The observed unique optical characteristics and involved physics may enable us to find a useful protocol to a variety of developing encoding applications using barcode nanomaterials.