Photocatalytically Powered Matchlike Nanomotor for Light-Guided Active SERS Sensing.

Surface enhanced Raman spectroscopy (SERS) is a powerful optical sensing technique that can detect analytes of extremely low concentrations. However, the presence of enough SERS probes in the detection area and a close contact between analytes and SERS probes are critical for efficient acquisition of a SERS signal. Presented here is a light-powered micro/nanomotor (MNM) that can serve as an active SERS probe. The matchlike AgNW@SiO2 core-shell structure of the nanomotors work as SERS probes based on the shell-isolated enhanced Raman mechanism. The AgCl tail serves as photocatalytic nanoengine, providing a self-propulsion force by light-induced self-diffusiophoresis. The phototactic behavior was utilized to achieve enrichment of the nanomotor-based SERS probes for on-demand biochemical sensing. The results demonstrate the possibility of using photocatalytic nanomotors as active SERS probes for remote, light-controlled, and smart biochemical sensing on the micro/nanoscale.