Simultaneous detection of Cd2+ and Pb2+ in food based on sensing electrode prepared by conductive carbon paper, rGO and CoZn·MOF (CP-rGO-CoZn·MOF)

Cd2+ and Pb2+ are two typical metallic pollutants in food. Therefore, it is of great significance to establish a method which can simultaneously detect them. Here, an electrochemical sensor was established to simultaneously detect Cd2+ and Pb2+ in food samples based on sensing electrode prepared by conductive carbon paper, rGO and CoZn·MOF (CP-rGO-CoZn·MOF). Under the optimized conditions, the proposed electrochemical sensor achieves simultaneous detection of Cd2+ and Pb2+ low to 0.565 nM (Cd2+) and 0.588 nM (Pb2+), respectively. Further selective experiments and repetitive experiments perform well. Spiked experiments find that the recovery rates of Cd2+ and Pb2+ in food samples are between 97.5% to 105.9% and 94.3%–109.6%, indicating the established electrochemical sensor owns a good response to the targets. Besides, relative standard deviations (RSD) of them are no more than 5.817%, showing its potential in practical applications.