Tailored SiO2‐TiO2 Aerogel/Ag Flexible Films as Stable SERS Substrates for Hazardous Materials Detection

Abstract Flexible surface‐enhanced Raman spectroscopy (SERS) substrates have received more and more attention for their non‐invasive sample collection ability. However, majority of them have poor stability and reproducibility because noble metal is easily oxidized and led to lose SERS activity. Herein, SiO 2 ‐TiO 2 ‐Ag hybrids aerogel (STAHA) material is first applied as a flexible SERS substrate for explosives and dyes long‐term sensitive detection. The sensitive non‐invasive detection of 3‐nitro‐1, 2, 4‐triazol‐5‐one (NTO) residues can be achieved with a limit of 1 × 10 −6 m by wiping sample collection method. Meanwhile, similar SERS sensitivity from long‐term (50 days) kept substrates is observed compared with fresh‐made substrates. This long‐term sensitivity is contributed to electronic transfer compensation from TiO 2 aerogel. This proposed flexible STAHA enrich the type of SERS substrates, and their long‐term sensitivity can provide a prospective application for trace analyses of explosives and other hazardous residues in criminal forensic, military, and security check.