Facile fabrication of multi-targeted and stable biochemical SERS sensors

Abstract

The direct transfer of single-crystalline Au nanowires (NWs) onto Au substrates was achieved by a simple attachment and detachment process. In the presence of a lubricant, Au NWs grown vertically on a sapphire substrate were efficiently moved to an Au substrate through van der Waals interactions. We demonstrate that the transferred Au NWs on the Au substrate can act as sensitive, reproducible, and long-term-stable surface-enhanced Raman scattering (SERS) sensors by detecting human α-thrombin as well as Pb2+ and Hg2+ ions. These three biochemically and/or environmentally important analytes were successfully detected with high sensitivity and selectivity by Au NW-SERS sensors bound by a thrombin-binding aptamer. Furthermore, the as-prepared sensors remained in working order after being stored under ambient conditions at room temperature for 80 days. Because Au NWs can be routinely transferred onto Au substrates and because the resultant Au NW-SERS sensors are highly stable and provide with high sensitivity and reproducibility of detection, these sensors hold potential for practical use in biochemical sensing.