Elevating electron transfer of recyclable SERS sensor using AuNPs/TiO2/Ti3C2 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 2 /Ti 3 C 2 heterostructures was developed for the detection and degradation of MG in aquatic products. Specifically, AuNPs/TiO 2 /Ti 3 C 2 heterostructures were synthesized by in situ oxidation and electrostatic adsorption based on Ti 3 C 2 nanosheets. The excellent photocatalytic and SERS performance of the AuNPs/TiO 2 /Ti 3 C 2 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 2 /Ti 3 C 2 is highly sensitive and recyclable. The detection limit of the sensor for MG is 8.91 × 10 −5  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.