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AKB: Biologische Physik
AKB 18: Ion Channels and Nanopores
AKB 18.1: Invited Talk
Wednesday, March 29, 2006, 15:30–16:00, ZEU 255
Synthetic Analogues of Biological Voltage-Gated Channels, Fabrication of Ion-Current Rectifiers and Protein Sensors — •Zuzanna Siwy — Department of Physics and Astronomy, University of California, Irvine, USA
We have fabricated a single asymmetric nanopore that mimics behavior of biological voltage-gated channels. The single pores have been prepared by the track-etching technique. The pores are conical in shape with diameter of the small opening down to several nm and the big opening in the micrometer range. We have designed two nanotube systems, which exhibit ion current rectification through two distinct mechanisms (i) through asymmetric potential energy profile for an ion inside the pore, and (ii) electro-mechanical gate placed at the entrance of the conical pore.
We have also designed single nanopore system, which produces voltage-dependent ion current fluctuations with the kinetics of opening and closing similar to voltage-gated biochannels.
I will also discuss application of synthetic voltage-gated nanopores as platforms in biosensing. The internal surfaces of the nanopores have been modified with a specific biochemical molecular-recognition agent (the *capture* agent, e.g., an antibody) which interacts specifically with a given biomolecule (the analyte) brought into contact with the nanotube. The binding interaction between the nanotube-bound capture agent and the solution-phase analyte is transduced as a change in the ion current that flows through the nanotube. We have demonstrated operation of the sensor for detection of ricin and immunoglobins.