Ti3C2 MXene/MoS2@AuNPs ternary nanocomposite for highly sensitive electrochemical detection of phoxim residues in fruits

Phoxim, extensively utilized in agriculture as an organothiophosphate insecticide, has the potential to cause neurotoxicity and pose human health hazards. In this study, an electrochemical enzyme biosensor based on Ti 3 C 2 MXene/MoS 2 @AuNPs/AChE was constructed for the sensitive detection of phoxim. The two-dimensional multilayer structure of Ti 3 C 2 MXene provides a robust framework for MoS 2 , leading to an expansion of the specific surface area and effectively preventing re-stacking of Ti 3 C 2 MXene. Additionally, the synergistic effect of self-reduced grown AuNPs with MoS 2 further improves the electrical conductivity of the composites, while the robust framework provides a favorable microenvironment for immobilization of enzyme molecules. Ti 3 C 2 MXene/MoS 2 @AuNPs electrochemical enzyme sensor showed a significant response to phoxim in the range of 1 × 10 −13  M to 1 × 10 −7  M with a detection limit of 5.29 × 10 −15  M. Moreover, the sensor demonstrated excellent repeatability, reproducibility, and stability, thereby showing its promising potential for real sample detection.