Ti3C2Tx MXene sensor for rapid Hg2+ analysis in high salinity environment.

Abstract Mercury is one of the leading chemicals of concern and receives much attention in environmental safety. It is of great necessity to develop advanced Hg2+ analysis method for rapid detection and monitoring. Field-effect transistor (FET) sensor, an emerging electronic sensor, has received great attention in environmental analysis since it has unique advantages in achieving rapid analysis of chemicals. Herein, an FET sensor is constructed with Ti3C2Tx MXene as the channel material to detect Hg2+ in water. The sensor displays rapid and selective response to Hg2+. Moreover, the sensor achieves satisfactory performance in Hg2+ detection in high salinity environment (1 M NaCl), which benefits its applications in real water analysis. Based on the investigation of sensing mechanism, the strong response of Ti3C2Tx MXene FET sensor to Hg2+ is due to the adsorption and reduction of Hg2+ to Hg+ on the Ti3C2Tx surface. This reported label-free Ti3C2Tx MXene platform can detect Hg2+ in high salinity environment with high specificity, which has significant application potential for on-site monitoring and risk assessment of Hg2+ in aqueous systems.