In this work we study the translocation process of a polymer through a nanochannel where a time dependent force is acting. Two conceptually different types of driving are used: a deterministic sinusoidal one and a random telegraph noise force. The mean translocation time presents interesting resonant minima as a function of the frequency of the external driving. For the computed sizes, the tran...

We have used the interface between a nanochannel and a microchannel as a tool for applying controlled forces on a DNA molecule. A molecule, with a radius of gyration larger than the nanochannel width, that straddles such an interface is subject to an essentially constant entropic force, which can be balanced against other forces such as the electrophoretic force from an applied electric field. ...

We demonstrate matrix-free pH gradient electrofocusing of proteins within an 85 nm deep nanochannel. In contrast to conventional isoelectric focusing where the fluid does not move, this pH gradient method traps protein molecules flowing through a channel by balancing electric forces due to pH-dependent protein charge and viscous drag forces caused by electro-osmosis. The nanoscale depth of the ...

Submitted for the MAR09 Meeting of The American Physical Society Rectification, Gating Voltage and Interchannel Communication of Nanoslot Arrays Due to Asymmetric Entrance Space Charge Polarization GILAD YOSSIFON, YU-CHEN CHANG, HSUEH-CHIA CHANG, University of Notre Dame — A nanochannel array with homogenous surface charge and height (i.e. uniform electro-chemical potential) but with asymmetric...

Abstract Nanochannel technology has emerged as a powerful tool for label‐free and highly sensitive detection of protein folding/unfolding status. However, utilizing the inner walls nanochannel array may cause multiple events even proteins with same conformation, posing challenges accurate identification. Herein, we present platform to detect unfolded through electrical optical signals using arr...

We present a method for measuring the fluorescence from a single molecule hundreds of times without surface immobilization. The approach is based on the use of electroosmosis to repeatedly drive a single target molecule in a fused silica nanochannel through a stationary laser focus. Single molecule fluorescence detected during the transit time through the laser focus is used to repeatedly rever...

We present a comprehensive study of the capillary force measured during the liquid nanodispensing of attoliter droplets with an atomic force microscope tip. Due to the presence of a nanochannel drilled at the tip apex and connected to a reservoir droplet deposited on the cantilever, we observe a large variety of force curves during the deposition process. We propose a numerical method which acc...