Flexible Au nanoparticles-decorated cellulose acetate SERS platform for Rhodamine 6G detection

Abstract Current limitations in surface-enhanced Raman scattering (SERS) substrates fabrication stem from the rigidity of substrate materials, its potential toxicity, and complex costly fabrication processes. Herein, a simple and environmentally friendly cellulose acetate-assisted photoreduction strategy was developed to construct Au nanoparticles loaded-cellulose acetate fibers as flexible SERS substrates. Crucially, cellulose acetate was used both as capping molecule and reducing agent for generating Au nanoparticles without any additional chemicals. Furthermore, the morphology and particle size of Au nanoparticles can be facilely tuned by adjusting the HAuCl 4 volume, photoreduction time and repeating photoreduction times. A key finding is that the SERS enhancement was controlled by an optimal trade-off between the size and density of Au nanoparticles on the cellulose acetate fibrous network. The optimized SERS-active substrate exhibited excellent sensitivity, good reproducibility and long-term stability to Rhodamine 6G molecules, revealing broad application prospects in SERS-based detection. This work not only provides a green, facile, and tunable method for constructing flexible SERS substrates but also offers new insights into sustainable sensor design.