In-situ grown MXene@PDA/MOF composites constructed electrochemical sensor for detecting trace l-cysteine

In this study, novel honeycomb-like morphology MXene@PDA/MOF composites were prepared in situ on the surface of MXene@PDA (polydopamine), combined with 2-methylimidazole and Zn 2+ . The characterizations of morphology and electrochemical properties show that MXene@PDA/MOF has large specific surface areas and outstanding electroconductibility. Furthermore, the MXene@PDA/MOF-based sensor was fabricated to detect l-cysteine (L-Cys). The response of differential pulse voltammetry (DPV) shows the current intensity increases as l-Cys concentration. Under the optimum conditions, DPV response shows a fine linear relationship with l-Cys concentration in a range of 0.01 – 5.0 μmol L −1 with the detection limit of 3.74 × 10 −9 mol L −1 . This sensor was used to detect l-Cys in real samples with recoveries of 100.34 % – 101.68 %. Thus, the MXene@PDA/MOF-based electrochemical sensor exhibits excellent selectivity, reproducibility, stability, and practicability.