Highly sensitive and reproducible surface-enhanced Raman scattering substrate based on Ag/ZnO nanosphere-shell arrays

Surface-enhanced Raman spectroscopy (SERS) has attracted considerable attention owing to its high sensitivity, long-term stability, and non-destructive detection capabilities. However, achieving both high sensitivity and reproducible signal output within a single SERS substrate remains a significant challenge in recent years. In this study, a highly sensitive and reproducible SERS substrate was successfully designed and fabricated based on Ag/ZnO spherical shell ordered arrays, leveraging the synergistic effects of localized surface plasmon resonance and charge transfer mechanisms, both of which contribute effectively to Raman signal enhancement. The SERS performance of the substrate depended on the thickness of the ZnO layer, with a maximum enhancement factor of 2.68 × 10 8 achieved using a 30 nm ZnO layer and rhodamine 6 G as the probe molecule. A detection limit as low as 10 −9 M was attained while maintaining a relative standard deviation below 6%. This exceptional performance arises from the synergistic contribution of the intense localized electromagnetic field generated by the spherical-shell architecture and the efficient charge transfer pathways enabled by the multifunctional Ag/ZnO bilayer structure. This work presents a promising strategy for the development of recyclable and ultra-sensitive SERS sensors applicable to biomolecular detection and organic pollutant monitoring. Download: Download high-res image (158KB) Download: Download full-size image