MXene supported Ag-MOFs composites for high performance electrochemical detection of heavy metal ions

Metal organic frameworks find promising application in the field of electrochemical sensing owing to the tunable electrochemical properties. In this study, silver metal based organic frameworks were synthesized by solvothermal method and modified through synthetic 2D electron rich MXene nanosheets. The synthesized nano-meterial, Ag-MOFs@MXene, was characterized by UV–Vis spectroscopy, FTIR, XRD, and SEM for optical, structural, and morphological analysis. The electroactive behavior of the synthesized material was investigated by cyclic voltammetry and electrochemical impedance spectroscopy. Ag-MOFs@ MXene were employed for the detection of Hg (II) and Pb (II) in simulated water systems. For the optimal working conditions of the fabricated sensor parameters like material's active mass, casted drop volume, pH and scan rate were investigated thoroughly against each individual ion. Sensor showed 2.527 μA ppb −1 and 1.079 μA ppb −1 sensitivity values for Hg (II) and Pb (II) ions along-with 1.552 ppb and 1.587 ppb limit of detections, respectively, across the linear range of 0.1–100 ppb. Besides this, the stability data showed only 22% current loss after 145 days storing it at 4 °C temperature. • Synthesis of MXene functionalized Ag-MOFs/GCE for electrochemical detection of selected HMIs. • Hg 2+ and Pb 2+ ions signified optimal response at pH 7 and 5 respectively. • Sensor demonstrated high selectivity and sensitivity. • Ag-MOFs@MXene/GCE exhibited 95% (25 °C) and 97% (4 °C) current retention over 20 days.