Detection of single ion channel activity on a chip using tethered bilayer membranes.
Membrane-bound ion channels are promising biological receptors since they allow for the stochastic detection of analytes at high sensitivity. For stochastic sensing, it is necessary to measure the ion currents associated with single ion channel opening and closing events. However, this calls for stability, high reproducibility, and long lifetimes. A critical issue to overcome is the low stability of the ion channel environment, that is, the bilayer membrane. A promising technique to surmount this is to connect the lower part of the membrane to a surface forming a tethered bilayer membrane. By reconstituting the synthetic ion channel, gramicidin A, into a tethered bilayer as part of a microchip design, we have been able to record the activity of single ion channels. The observed activity was compared with that obtained by a conventional electrophysiology method, tip dipping, to confirm its authenticity. These findings allow for the construction of stable biosensors based on ion channels and provide a novel technique for the characterization of ion channel activity.
Andersson
Martin
M
Department of Chemistry, University of Florida, Gainesville, FL 32611, USA.
Keizer
Henk M
HM
Zhu
Chenyu
C
Fine
Daniel
D
Dodabalapur
Ananth
A
Duran
Randolph S
RS
D001105:Archaea / Q000378:metabolism; D001407:Bacillus / Q000378:metabolism; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004566:Electrodes; D004594:Electrophysiology / Q000295:instrumentation; D006046:Gold / Q000737:chemistry; D006096:Gramicidin / Q000737:chemistry; D007473:Ion Channels / Q000737:chemistry*; D007477:Ions; D008051:Lipid Bilayers / Q000737:chemistry*; D008564:Membrane Potentials; D008956:Models, Chemical; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013269:Stochastic Processes
D007473:Ion Channels; D007477:Ions; D008051:Lipid Bilayers; D006096:Gramicidin; D006046:Gold