Reasonable design of an MXene-based enzyme-free amperometric sensing interface for highly sensitive hydrogen peroxide detection

Sensitive detection of H₂O₂ in the nano- to micromolar range is critical for health monitoring and disease diagnosis. Two-dimensional transition metal carbides or/and nitrides (called MXenes, MXs) have excellent potential applications in the electrochemical field due to their outstanding electrical conductivity and catalytic properties. In this work, Ti₃C₂T_x (MX) was employed for the construction of a sensitive and enzyme-free electrochemical sensing interface for the detection of hydrogen peroxide (H₂O₂) through a simple and effective method. Prussian blue (PB) was electrochemically deposited on the surface of a glassy carbon electrode (GCE). Chitosan (CS) and MX were sequentially dripped onto the PB modified GCE surface. The reasonable fabrication of the MX/CS/PB/GCE sensing interface presented good electrochemical sensing performance towards H₂O₂ with a low limit of detection (4 nM), a wide linear range from 50 nM to 667 μM and good selectivity. The proposed MX/CS/PB/GCE has been proven to monitor H₂O₂ in food samples and biological samples with recoveries between 94.7% and 100.3%. This work has made a beneficial attempt and research for exploring and expanding the application of MXs in the field of electrochemical sensing.