Label-free SERS study of galvanic replacement reaction on silver nanorod surface and its application to detect trace mercury ion

摘要

It is significant to explore a rapid and highly sensitive galvanic replacement reaction (GRR) surface enhanced Raman scattering (SERS) method for detection of trace mercury ions. This article was reported a new GRR SERS analytical platform for detecting Hg(II) with label-free molecular probe Victoria blue B (VBB). In HAc-NaCl-silver nanorod (AgNR) substrate, the molecular probe VBB exhibited a strong SERS peak at 1609?cm?1. Upon addition of Hg(II), the GRR occurred between the AgNR and Hg(II), and formed a weak SERS activity of Hg₂Cl₂ that deposited on the AgNR surfaces to decrease the SERS intensity at 1609?cm?1. The decreased SERS intensity was linear to Hg(II) concentration in the range of 1.25–125?nmol/L, with a detection limit of 0.2?nmol/L. The GRR was studied by SERS, transmission electron microscopy and other techniques, and the GRR mechanism was discussed.