Preparation of Ag–TiO 2 /MXene composite material for electrochemical detection of paraquat

Mxenes, a general term for a novel class of two-dimensional carbon–nitrogen compounds, which attracted extraordinary attention because of their unique electrochemical property. In this paper, an Ag-TiO 2 /MXene composite material was prepared for paraquat (PQ) detection by differential pulse voltammetry (DPV). It was found that the detection limit reached as low as 0.01 μM and linear range was from 0.05 to 15 μM (split into two sections: 0.05 to 1 μM and 1 μM to 15 μM). The Ag-TiO 2 /MXene composite electrode material exhibits excellent anti-interference properties to the species including the ions such as Cu 2+ , Na + , Ca 2+ , Zn 2+ , Cl − , SO 4 2− and biomass molecules such as glucose, ascorbic acid and uric acid. In the presence of organophosphorus pesticides, the electrode also showed good anti-interference. The excellent paraquat detection capability of the Ag–TiO 2 /MXene electrode material should be attributed to the synergistic effect obtained by decorating Ag and TiO 2 on MXene. In conclusion, the functionalization of MXenes through surface-modification provided a feasible route for ultrasensitive electrochemical sensors construction.