Paper electrophoretic enrichment-assisted ultrasensitive SERS detection

Abstract

To achieve sensitive detection of trace substances in fluids by surface-enhanced Raman spectroscopy (SERS), effective enrichment of molecules at subwavelength regions (hot spots) with a large enhancement is adopted. In this work, a glass fibre paper with Ag nanoparticles (AgNPs) is employed for electrodynamic enrichment of analytes in fluids by paper electrophoresis integrated with field amplification sample stacking (FASS) and capillary effects to obtain both Raman and SERS convenient and sensitive detection. With the help of electrophoretic enrichment on the glass fibre paper and surface plasmon enhancement on the AgNPs, this paper electrophoretic enrichment could improve the detection limit of Raman and SERS detection by more than an order of magnitude, even achieving a SERS detection limit of 10−17 M for Nile Blue A. Furthermore, this flexible SERS detection method can also detect trace organic contaminants at the ppt level in aquaculture and food applications.