A highly sensitive enzyme catalytic SERS quantitative analysis method for ethanol with Victoria blue B molecular probe in the stable nanosilver sol substrate

Abstract

Using AgNO3 as precursor, a stable silver nanosol with strong SERS activity was prepared rapidly by light-wave procedure. A highly sensitive SERS quantitative analysis method for ethanol was developed, coupled the alcohol oxidase catalytic reaction with the Fe2+ catalytic reaction that the produced hydroxyl radicals not only oxidized the silver atoms on the nanosilver surface to form more dispersed and small size nanosilvers with weak SERS effect, but also oxidized the molecular probe Vitoria blue B (VBB) to fade. With the increasing of ethanol concentration, the more nanosilver and probe molecules were oxidized, resulting in SERS intensity decreasing at 1615 cm−1. The decreased SERS intensity was linear to ethanol in the range of 0.008–0.40 mg/L, with a detection limit of 3 μg/L. This method was applied to determination of ethanol in beer and serum samples, with satisfactory results.