Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Proximal Capture Dynamics for a Single Biological Nanopore Sensor



John J. Kasianowicz


Single nanopore sensors enable capture and analysis of molecules that are driven to the pore entry from bulk solution. However, the distance between an analyte and the nanopore opening limits the detection efficiency. A theoretical basis for predicting particle capture rate is important for designing modified nanopore sensors, especially for those with covalently tethered reaction sites. Using the Finite Element Method, we develop a soft-walled-electrostatic-block (SWEB) model for the alpha-hemolysin channel that produces a vector map of drift-producing forces on particles diffusing near the pore entrance. The maps are then coupled to a singleparticle diffusion simulation to probe capture statistics and to track the trajectories of individual particles on the μs to ms time scales. The investigation enables evaluation of the interplay among the electrophoretic, electroosmotic, and thermal driving forces as a function of applied potential. The findings demonstrate how the complex drift-producing forces compete with diffusion over the nanoscale dimensions of the pore. The results also demonstrate the spatial and temporal limitations associated with nanopore detection and offer a basic theoretical framework to guide both the placement and kinetics of reaction sites located on, or near, the nanopore cap.
Journal of Physical Chemistry


nanopore, biosensor


Kasianowicz, J. (2015), Proximal Capture Dynamics for a Single Biological Nanopore Sensor, Journal of Physical Chemistry (Accessed June 17, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created June 23, 2015, Updated November 6, 2017