DNA-based detection of mercury(II) ions through characteristic current signals in nanopores with high sensitivity and selectivity.

We report single-molecule detection of Hg(2+) by threading an Hg(2+)-mediated DNA duplex through α-hemolysin nanopores, which generates characteristic three-level current patterns and enables the unambiguous detection of Hg(2+). This strategy precludes any background interference and features high sensitivity and selectivity. Moreover, the platform could be readily integrated with aptamers and molecular beacons, offering extended possibilities for the construction of a new DNA-based nanopore sensing system.