Silver Nanoparticle-Decorated Chitosan Aerogels as Three-Dimensional Porous Surface-Enhanced Raman Scattering Substrates for Ultrasensitive Detection.

Surface-enhanced Raman scattering (SERS) has attracted widespread attention because of its high sensitivity and label-free detection capabilities. Here, chitosan aerogels decorated with Ag nanoparticles (CAA) are used as a three-dimensional (3D) SERS substrate to achieve ultrasensitive detection. The CAA produces a high specific surface area and high porosity, which generates numerous hot spots and adsorption sites for SERS. With crystal violet as a probe molecule, a SERS enhancement factor of 1.4 × 10⁹ was realized, with a detection limit of 10^–13 M. Furthermore, quantitative detection in the 10^–5–10^–10 M range and good reproducibility were achieved. This work proposes a cost-effective aerogel-based SERS substrate with high sensitivity and reproducibility. [ABSTRACT FROM AUTHOR]