Recyclable SERS monitoring of food quality based on the shrubby morphology of titania oxide-triggered electromagnetic “hotspots”

• Titania oxide with a shrubby morphology was prepared on carbon cloth to trigger SERS “hotspots” with a high-density. • The structure-dependent optical performance including SERS and photocatalysis was investigated for these as-prepared CC/TiO 2 /Ag hybrid substrates. • An actual detection of quercetin in teas was achieved by the self-cleaning SERS substrate. Constructing of plasmonic substrate with the capability of detecting nutritional food quality will soon be emerged as the frontier research directions with broad prospects in surface-enhanced Raman scattering (SERS) technology ascribed to an improvement of living standards. Herein, a novel TiO 2 framework with a shrubby morphology was successfully constructed on carbon cloth (CC) matrix to trigger significantly enhanced electromagnetic “hotspots” after dense Ag network with numerous sharp corners and edges was formed by a photo-induced reduction. Particularly, the structure-dependent optical performance was investigated for these as-prepared CC/TiO 2 /Ag hybrid substrates, screening out an optimal one with an enhancement factor of 6.38 × 10 7 . Regarding a prominent photocatalytic efficiency ascribed to the high electron-hole separation efficiency assisted by the CC matrix and Ag decoration, a recyclable SERS-based monitoring of quercetin (QR) was achieved in teas, demonstrating recovery values distributed from 88.9% to 106.4%. The strategy proposed here opened a new way to create high-density “hotspots” for multifunctional SERS substrates, which might play a crucial role in food quality monitoring applications.