Ultrasensitive Mercury Ion Detection Using DNA Functionalized Molybdenum Disulfide Nanosheet/Gold Nanoparticle Hybrid Field Effect Transistor Device
Mercury, one of the most harmful pollutants in water, has a significant negative impact on human health. The molybdenum disulfide (MoS2) nanosheet, due to its unique electronic properties, is a promising candidate for high performance sensing materials. Here, we report a DNA functionalized MoS2 nanosheet/gold nanoparticle hybrid field effect transistor (FET) sensor for the ultrasensitive detection of Hg2+ in an aqueous environment. Specific DNA was used in the hybrid structure as the capture probe for the label free detection. By monitoring the electrical characteristics of the FET device, the performance of the sensor was investigated. Our sensor shows a rapid response (1 2 s) to Hg2+ and an ultralow detection limit of 0.1 nM, which is much lower than the maximum contaminant level (MCL) for Hg2+ in drinking water (9.9 nM) recommended by the U.S. Environmental Protection Agency (EPA) In addition, the sensor shows a high selectivity to Hg2+ compared with other interfering metal ions, e.g. As5+ Cd2+ Pb2.