Abstract
Understanding the extent of cadmium (Cd) contamination and its impact on the food industry and ecosystems is crucial; to this end, electrochemical methods provide sensitive and rapid responses for the in situ detection of heavy metal ions. In this paper, a sensitive Cd(2+) electrochemical sensor was constructed by using a composite material composed of biomass-derived porous carbon and manganese dioxide (MnO(2)/KLSC). The composite was demonstrated to have a porous structure with quasi-cubic MnO(2) particles evenly distributed on the carbon matrix. Using MnO(2)/KLSC as the electrode material, a simple electrochemical sensing platform was fabricated for the detection of Cd(2+). The electrochemical analysis showed that the Cd(2+) sensor has good performance, with a linear detection range of 0.01-80.0 μmol/L and a detection limit of 9.8 nmol/L. Furthermore, the sensor shows excellent repeatability, reproducibility, and good anti-interference. The sensor was successfully applied to analyze rice and sea water samples, demonstrating satisfactory recovery rates. The good performance of MnO(2)/KLSC/GCE can be attributed to the excellent electrical conductivity, enlarged active surface area, and good electron transfer capability.