A novel electrochemical strategy based on MXene@rGO composite aerogel-doped UiO-66-NH2 for simultaneous detection of cadmium and lead in grain and water samples

•MXene@rGO aerogel and UiO-66-NH2 synergistically enhance sensor’s sensitivity.•The LODs of Cd2+ and Pb2+ are 0.46 ppb and 0.40 ppb, respectively.•Accurate simultaneous detection of Cd2+ and Pb2+ in food and water was realized. Herein, a novel electrochemical sensing platform is designed for the simultaneous detection of Cd2+ and Pb2+, using MXene@rGO composite aerogel-doped UiO-66-NH2. The MXene@rGO composite aerogel not only serves as the support structure for UiO-66-NH2, but also improves the conductivity of the composite by accelerating the electron transport in the matrix. The amino group of UiO-66-NH2 offers binding sites for heavy-metal ions, and the existence of PhNH2/PhNH3+ in the composite promotes the redox processes of the metal ions to be detected on the electrode surface. The proposed sensing strategy can detect Cd2+ and Pb2+ independently and concurrently, with detection limits of 0.46 ppb and 0.40 ppb, respectively. Remarkably, when this strategy is used for simultaneous detection of Cd2+ and Pb2+ in grain and water samples, it exhibits excellent accuracy and reliability, aligning with the standard method (e.g., AAS and ICP-MS) demonstrating considerable promise in practical applications.