SERS-active silver nanoparticle assemblies on branched Cu2O crystals through controlled galvanic replacement†
Abstract
We here demonstrate the fabrication of Ag nanoparticle (NP) assemblies on branched Cu2O crystals through a galvanic replacement reaction process, where the branched Cu2O morphology can be well maintained by controlling the reaction environment (acid introduced to initiate the reaction). Cu2O was transferred into soluble Cu2+ species, which renders a clean surface of Ag NPs. The as-fabricated Ag NP assemblies can be used as promising SERS-active substrates for molecule detection, with a detection sensitivity of 10−9 mol L−1 towards both target molecules, MB and RhB. We believe galvanic replacement using Cu2O as a sacrificing template can also be applied to synthesize noble metal (Au, Pt, Pd) NPs or NP assemblies for various applications.