Modulation of a gated ion channel admittance in lipid bilayer membranes.
A future class of amperometric biosensors may utilize gated ion channels such as acetylcholine and glutamate receptors as chemical detection components. In this study, bilayer lipid membranes containing voltage-dependent anion channels (VDAC) were used to model an ion-channel-based biosensor which could continuously monitor AC amperometric changes resulting from induced changes in channel conductance. The in-phase and quadrature components of the induced alternating membrane current were monitored as a function of the applied DC offset voltage which was superimposed on the sinusoidal test voltage. The accuracy and sensitivity of the AC-measured VDAC response was dependent on the magnitude of the AC test voltage relative to the DC offset necessary for channel closure. The VDAC channel appears to be a suitable model protein for AC impedance-based biosensor fabrication.
Stenger
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DA
Code 6090, Naval Research Laboratory, Washington, DC 20375.
Cribbs
D H
DH
Fare
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TL
D015374:Biosensing Techniques; D004563:Electrochemistry; D007473:Ion Channels; D008051:Lipid Bilayers
D007473:Ion Channels; D008051:Lipid Bilayers