Electrical, optical, and docking properties of conical nanopores.

The diffusion-influenced translocation behavior of individual nanoparticles upon passage through a conical nanopore has been elucidated by using a pressure-reversal, resistive-pulse technique, as reported by Lan and White in this issue of ACS Nano. We outline here some recent progress in conical nanopore analysis, and we present some prospects for future developments. Compared to cylindrical nanopores, the geometric change brought about by tapered nanopores causes a dramatic difference in electrical and optical properties. Such conical nanopores may also be integrated into microfluidic chips to capture cells or nanoparticles, one per nanopore, and then to release them. These advances hold the promise of making conical nanopores useful as highly efficient actuators and sensors.