Tuning the SERS Capabilities of ZnO Nanowire Arrays Functionalized with Au Quantum Dots for Highly Sensitive Detection of Methylene Blue

Abstract

The development of a surface enhanced Raman scattering (SERS) substrate capable of sensing the target analyte at low concentration has always been demanding. In this prospective, ZnO−Au quantum dots (QDs) hybrid structure with tunable surface properties and high chemical stability is considered a promising material for SERS applications. Here, a novel ZnO@Au QDs hybrid structures with various amounts of Au QDs (ZnO−Aux QDs, where x=0.2, 0.4, 0.6 and 1.0) was synthesized by employing solvothermal along with electrodeposition approach. The optimized substrate, ZnO@Au QDs (0.6) exhibits excellent SERS sensitivity for the detection of MB up to 1 nM with a good reproducibility. The chemical and compositional analysis show that the surface defects are formed due to the interface interactions which not only promote charge transfer between ZnO nanowires and Au QDs complex but also enhanced the Raman scattering of target analyte. The developed substrate demonstrates excellent SERS uniformity which makes them reliable choice for the detection of multi‐analyte for practical applications.