The utilization of silver salts of aromatic thiols as core materials of SERS-based molecular sensors

Silver salts of aromatic thiols are one class of organic-inorganic heterostructured materials, showing peculiar photoreaction characteristics. When an argon ion laser is exposed to silver benzenethiolate (AgBT), for instance, its Raman spectrum changes over time, eventually becoming the same as the surface-enhanced Raman scattering (SERS) spectrum of benzenethiol on a roughened Ag substrate. AgBT and its analogs can thus be used as a core material of molecular sensors operating via SERS; we demonstrate this specifically, by monitoring the SERS peaks of BT, in which biotinylated AgBT selectively recognizes streptavidin molecules down to concentrations of 10(-11) g ml(-1) (i.e. similar to 0.2 pM). Since numerous silver thiolates can be used as the core material, multiple bioassays are readily accomplished using the present methodology. Copyright (C) 2008 John Wiley & Sons, Ltd.