Controllable preparation of graphene oxide/metal nanoparticle hybrids as surface-enhanced Raman scattering substrates for 6-mercaptopurine detection

In this contribution, a new simple and cost-effective strategy for the preparation of hybrids of graphene oxide (GO) and metal nanoparticles (MNPs) through the mediation of polyethyleneimine (PEI) molecules was reported. PEI molecules as cationic polymers could effectively attach onto the surface of GO for further negative MNP adsorption. By this process, gold and silver nanoparticles are assembled on GO with high efficiency. This method has also been successfully applied to the assembly of metal nanoparticles and carbon nanotubes (CNTs), indicating that this method is general. Furthermore, the as-prepared graphene oxide/silver nanoparticle (GO/AgNP) hybrids have been used as perfect surface enhanced Raman scattering (SERS) substrates with an enhancement factor of 1.5 × 105 and successfully applied for the sensitive and selective detection of 6-mercaptopurine (6MP) in pharmaceutical tablets with satisfactory results.