Reusable SERS Substrate Based on AuNP/PS‐b‐P2VP Nanocomposites With Photocatalytic Activity

ABSTRACT In this study, thin films of presynthesized gold nanoparticles assembled in reconstructed poly (styrene‐block‐2‐vinylpyridine) (PS‐ b ‐P2VP) thin films were utilized for sensing and UV‐induced degradation of analytes. The reusability of the substrates was assessed using Nile Blue and Rhodamine 6G as molecular probes at a concentration of 1.0 × 10 −4 mol L −1 . Surface‐enhanced Raman spectroscopy (SERS) mapping of the bands at 594 and 615 cm −1 for Nile Blue and Rhodamine 6G, respectively, demonstrated a uniform SERS signal distribution across the analyzed area, showing homogeneous dye adsorption. The nanocomposite substrates demonstrated excellent reusability, maintaining their SERS activity and degradation efficiency over four consecutive cycles. Theoretical and experimental evidence suggests that dye degradation is primarily driven by hot holes generated via interband transitions in AuNPs under UV excitation. This work demonstrates an effective dual‐function platform capable of both sensing and hot‐hole‐mediated photocatalysis, highlighting its potential for sustainable and reusable SERS applications.