Biothiol-Functionalized Cuprous Oxide Sensor for Dual-Mode Sensitive Hg Detection.

Hg ions are one of the highly poisonous heavy metal ions in the environment, so it is urgent to develop rapid and sensitive detection platforms for detecting Hg ions. In this work, a novel electrochemical and photoelectrochemical dual-mode sensor (l-Cys-CuO) was successfully fabricated, and the sensor exhibits a satisfactory detection limit (0.2 and 0.01 nM) for the detection of Hg, which is far below the dangerous limit of the U.S. Environmental Protection Agency. The linear ranges of dual-mode Hg detections were 0.33-3.3 and 0.17-1.33 μM, respectively. Moreover, the sensor shows desirable stability, selectivity, and reproducibility for detecting Hg ions. For river water samples, the recoveries of 96.6-101.4% (electrochemical data) and 93.0-105.6% (photoelectrochemical data) were obtained, indicating that the sensor could be successfully applied in the determination of Hg ions in environmental water. Therefore, the designed sensor has a potential in the trace-level detection of Hg ions.