Nanopore-Based Metal Ion Detection and Metal Ion-Mediated Nanopore Sensing

With the continuous development of nanotechnology, single-molecule nanopore detection has become a popular research topic. In this review, we summarize the application of biological nanopores for metal ions detection as well as overview the function of metal ions in the ion-mediated nanopore detection of different analytes in recent decades. According to the previous reports, biological nanopores utilize two strategies to detect metal ions. First, the specific binding sites are engineered in the nanopore to slow down the translocation rate of metal ions, resulting in the diverse specific current blockage signals. Secondly, the external molecule probes are added in the detection system to interact with metal ions, leading to the characteristic changes in the signals. At the same time, the external addition of metal ions into the nanopore detection systems enhances the sensitivity and selectivity through the changes of pore charges, the coordination with analytes or indirect detection. This review provides a summary on the role of metal ions in the application of nanopore detection technology.