Preparation and Optical Properties of Au Nanoparticle “Sandwich” Structure (AuNPs/ZNNs/AuNPs) Substrate Based on ZnO Nanosheets Template

Abstract Surface enhancement Raman scatting (SERS) substrate was synthesized by two-step electrodeposition method based on ZnO nanosheets (ZNNs) template. ZNNs membrane was prepared via first-electrodeposition by using zinc nitrate hexahydrate (ZnNO3•6H2O) as the precursor. Subsequently, an Au seed layer was coated on the ZNNs membrane substrate using ion sputtering apparatus. Finally, Au nanoparticles composite membrane was obtained by the second-electrodeposition growth process of Au nanoparticles in chlorogenic acid (HAuCl4•4H2O) solution. The Au nanoparticles composite membrane could be served as an activity SERS substrate, and it showed that ZNNs are mutually hinged and grow vertically ITO substrate and Au nanoparticles grew along the (111) crystalline orientation. Results demonstrate that Au nanoparticles with an average diameter of 50 nm are uniformly deposited on the surface of ZNNs template, and the as-prepared AuNPs/ZNNs/AuNPs “sandwich” structures membrane was a high activity and sensetivity SERS substrate, it showed a rather low detection limitation of 10-12 mol/L for R6G solution.