Electrokinetic Nanorod Translocation through a Dual-Nanopipette

Glass nanopipettes, as important sensing tools, have attracted great interest due to their wide range of applications in detecting single molecules, nanoparticles, and cells. In this study, we investigated the translocation behavior of nanorod particles through dual-nanopipettes using a transient continuum-based model based on an arbitrary Lagrangian-Eulerian approach. Our findings indicate that the translocation of nanorods is slowed down in the dual-nanopipette system, especially in the dual-nanopipette system with a nanobridge. These results are in qualitative agreement with previous experimental findings reported in the literature. Additionally, the translocation of nanorods is influenced by factors such as bulk concentration, initial location of the nanorod, and surface charge of the nanopipette. Notably, when the surface charge density of the nanopipette is relatively high and the initial location of the nanorod is in the reservoir, the nanorod can hardly enter the nanopipette, resulting in a relatively low translocation efficiency. However, the translocation efficiency can be improved by initially positioning the nanorod in one of the barrels. The resulting dual-blockade current signal can be used to correlate the characteristics of the nanorod.