Tribo-electrophoresis preconcentration enhanced ultra-sensitive SERS detection

Abstract

Attracting target molecules in solution to electromagnetic hot spots is one of the most important problems in the application of surface-enhanced Raman spectroscopy (SERS). In this work, an ultrasensitive SERS detection system with electrokinetic preconcentration is proposed, in which triboelectric nanogenerator (TENG) is employed to provide the electrostatic driving force for molecular enrichment on SERS substrate. During TENG operation, an electric field is generated in solution and provides sufficient driving force for the movement of target molecules. Thanks to the unique output characteristics of TENG, effective enrichment of molecules in triboelectric preconcentration (TEPC) is achieved in 30 s, which exhibits much higher efficiency compared to the enrichment in 10 min with a DC source. Moreover, the TEPC assisted SERS detection system exhibits excellent sensitivity with the limit of detection (LOD) at 10−15 M. Furthermore, a self-powered TEPC assisted SERS system is designed, which could use environmental mechanical energy and realize outdoor real-time sensitive detection.