In situ regulation nanoarchitecture of Au nanoparticles/reduced graphene oxide colloid for sensitive and selective SERS detection of lead ions

In this work, the colloid of Au nanoparticles (AuNPs)/reduced graphene oxide (rGO) was synthesized by growth AuNPs on rGO via the reduction of HAuCl4 on graphene oxide (GO) nanosheets. The nanoarchitecture of the colloid could be controllably regulated through in-situ Pb2+-enhanced gold leaching reaction, which made the colloid be a flexible surface-enhanced Raman scattering (SERS) platform for Pb2+ detection. Upon the addition of Pb2+, the Raman signal of graphene underwent significant descent due to the decrease of the amount of the hot spots, which was originated from Pb2+-accelerated dissolution of AuNPs on the graphene surface in the present of thiosulfate (S2O32-). Based on the change of SERS signal through in situ regulation the nanoarchitecture of the colloid, a sensitive and selective strategy for Pb2+ measurement was developed with a linear range from 5 nM to 4 mu M as well as a low detection limit of 1 nM. Furthermore, the SERS-based method was applied for the determination of Pb2+ in water samples with satisfactory results. (C) 2015 Elsevier Inc. All rights reserved.