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

Cd and Pb 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 Cd and Pb 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 Cd and Pb low to 0.565 nM (Cd) and 0.588 nM (Pb), respectively. Further selective experiments and repetitive experiments perform well. Spiked experiments find that the recovery rates of Cd and Pb 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.