Ultrasensitive and Selective Mercury(II) Ion Detection with a Glass Nanopore

The detection of heavy metal ions is of great importance to the human health and environment. At present, the portability and sensitivity of heavy metal ion detection remains a challenge in application research. In our works, a novel nanopore sensing technology for mercury ion detection is proposed based on nanopore surface charge modulation at the adsorption of mercury ions. The sensor is made of reusable glass nanopore, and functionalized with DNA adaptors that is selective of mercury ions. The surface charge of nanopore inner wall is modulated by the concentration of mercury ion in solution, which is analyzed by the rectification ratio of the current-voltage curve. A detection limit of below 0.1 nmol/L is obtained, which is far below the drinking water standard.