Elevating electron transfer of recyclable SERS sensor using AuNPs/TiO/TiC heterostructures for detection of malachite green in sunfish.

Malachite green (MG)-contaminated aquatic products pose a serious threat to animal and human health. Hence, a novel recyclable surface-enhanced Raman scattering (SERS) substrate based on AuNPs/TiO/TiC heterostructures was developed for the detection and degradation of MG in aquatic products. Specifically, AuNPs/TiO/TiC heterostructures were synthesized by in situ oxidation and electrostatic adsorption based on TiC nanosheets. The excellent photocatalytic and SERS performance of the AuNPs/TiO/TiC was demonstrated by Density functional theory (DFT) calculations and experimental results, which was attributed to the enhancement of charge transfer (CT) after the formation of heterostructures. The results demonstrate that AuNPs/TiO/TiC is highly sensitive and recyclable. The detection limit of the sensor for MG is 8.91 × 10 mg/L. The sensor can be recycled for five times under the condition of light, and shows satisfactory self-cleaning performance in the food matrix, providing a possible alternative solution for the recyclable detection of MG.