An Fe-MOF/MXene-based ultra-sensitive electrochemical sensor for arsenic(III) measurement

The Fe-metal organic framework decorated MXene (Fe-MOF/MXene) was in-situ synthesized by one-step hydrothermal method in the presence of MXene. Using Fe-MOF/MXene as modifier, the obtained Fe-MOF/MXene electrode presented excellent electrochemical activity due to the high surface area and good conductivity of MXene. A sensitive arsenite electrochemical sensor was fabricated based on the strong As-hydroxyl bonding at the Fe-MOF/MXene electrode, confirmed by X-ray photoelectron spectroscopy. Cyclic voltammetry characterization indicated that MXene facilitated the charge transfer with enhanced electrochemical response. The Fe-MOF/MXene modified electrode exhibited super-high current response to As(III) by square wave anodic stripping voltammetry, with extremely high sensitivity (8.94 µA·(ng·L−1)−1·cm−2) and super-low limit of detection (0.58 ng·L−1). The analysis of the real water demonstrated that the Fe-MOF/MXene-based sensor was feasible for the detection of As(III) in practical application.