Electrochemical Sensor for Cd <sup>2+</sup> Detection Based on Carbon Fiber Paper Sequentially Modified With CoMOF, AuNPs, and Glutathione
Yanli Qi, Xiaolong Chen, Shasha Liu, Ping Yang, Suyi Zhang, Changjun Hou, Danqun Huo
Abstract
Cadmium ion (Cd 2+ ) is one of the toxic heavy metals in the environment. Even small amounts of Cd 2+ may cause environmental pollution and threaten human life and health. Here, an electrochemical sensor for Cd 2+ detection was established using a complex of carbon fiber paper (CFP), CoMOF, AuNPs, and glutathione as the conductive substrate (CFP/CoMOF/AuNPs/GSH). Compared with traditional methods for heavy metals detection, electrochemistry owns the advantages of high sensitivity, easy miniaturization, and portability. In addition, general conductive substrate is replaced by a new nanomaterial, CFP/CoMOF/AuNPs/GSH, which improves the performance greatly. In the presence of Cd 2+ , GSH is chelated to Cd 2+ , resulting in a redox peak appearing around −0.84 V. Thus, a sensitive and easily portable electrochemical sensor for Cd 2+ detection has been developed. Under optimal conditions, the established electrochemical sensor achieves Cd 2+ detection low to 1 nM. Selectivity and reproducibility experiments show that the sensor has good analytical performance. This provides a direction for the use of electrochemistry to detect heavy metal ions.