One-pot green synthesis of graphene oxide/gold nanocomposites as SERS substrates for malachite green detection

Abstract

In this contribution, graphene oxide/gold nanoparticle (GO/AuNPs) hybrids were in situ fabricated through a green one-pot procedure by using tyrosine as an environment friendly and biocompatible reducing agent, which can be used as highly efficient surface enhanced Raman scattering (SERS) substrates with the enhancement factor at 3.8 × 10³. The as-prepared GO/AuNPs hybrids have good biocompatibility, providing the prospect of applications for biomedicine determinations. In addition, taking the advantages of the electromagnetic and chemical enhancement mechanism and the high affinity of GO and AuNPs towards positive dyes, a sensitive, selective and label-free malachite green (MG) detection method was demonstrated. The SERS measurement showed that the minimum detection concentration of MG in water was as low as 2.5 μmol L⁻¹ with a linear response range from 2.5 to 100 μmol L⁻¹ (R² = 0.996). Moreover, this method can be applied to detect MG in a fishery water sample with satisfactory results.