Improved SERS Performance on Ag-Coated Amorphous TiO<sub>2</sub> Random Nanocavities by the Enhanced Light–Matter Coupling Effect
Yingying Huang, Sihang Zhang, Shouxiang Jiang, Jiangtao Xu
Abstract
Flexible surface-enhanced Raman spectroscopy (SERS) substrates have garnered more and more attention due to their noninvasive sample collection ability. However, the improvement of SERS performance gradually reaches a bottleneck with numerous studies on exploration of active materials. In this study, we constructed an Ag@TiO 2 @cotton SERS substrate with randomly distributed TiO 2 nanocavities, which can generate a strong coupling cavity mode, thus dramatically enhancing SERS activities. The prepared SERS substrates demonstrate high detection sensitivity, with a limit of 10 –10 M for MB solution, an impressive enhancement factor (EF) of 2.7 × 10 8, excellent signal reproducibility, and remarkable stability. Furthermore, the proposed material allows the sensitive detection of MG with a limit of 1.0 × 10 –10 M through a wiping fish collection method. These flexible Ag@TiO 2 @cotton substrates expand the range of available SERS substrates, and their easy fabrication method and long-term sensitivity hold promise for the trace analysis of harmful substances.