SERS substrates formed by gold nanorods deposited on colloidal silica films
- Equal contributors
1 Institute of Laser and Information Technologies, Russian Academy of Sciences, 2 Pionerskaya Ulitsa, Moscow, Troitsk 142190, Russia
2 Institute of Biochemistry and Physiology of Plants and Microorganisms, Russian Academy of Sciences, 13 Prospekt Entuziastov, Saratov 410049, Russia
3 Central Research Technological Institute “TECHNOMASH”, 4, I. Franko Ulitsa, Moscow 121108, Russia
4 Saratov State University, 83 Astrakhanskaya Ulitsa, Saratov 410012, Russia
Nanoscale Research Letters 2013, 8:250 doi:10.1186/1556-276X-8-250Published: 22 May 2013
We describe a new approach to the fabrication of surface-enhanced Raman scattering (SERS) substrates using gold nanorod (GNR) nanopowders to prepare concentrated GNR sols, followed by their deposition on an opal-like photonic crystal (OPC) film formed on a silicon wafer. For comparative experiments, we also prepared GNR assemblies on plain silicon wafers. GNR-OPC substrates combine the increased specific surface, owing to the multilayer silicon nanosphere structure, and various spatial GNR configurations, including those with possible plasmonic hot spots. We demonstrate here the existence of the optimal OPC thickness and GNR deposition density for the maximal SERS effect. All other things being equal, the analytical integral SERS enhancement of the GNR-OPC substrates is higher than that of the thick, randomly oriented GNR assemblies on plain silicon wafers. Several ways to further optimize the strategy suggested are discussed.