Impedance spectroscopy of bilayer membranes on single crystal silicon

Bilayer membranes on solid supports are being developed as electrically addressable, robust, surface-supported membrane mimetics. These platforms are being explored for basic ion channel research as well as for detection and analyte sensing. The formation of bilayer membranes on semiconductor surfaces is an important step in device integration for transistor and sensor arrays. Here, the authors review the contributions to the impedance response of bilayer membranes on semiconductors, and highlight the important issues for experimental measurements. The authors also present experimental results for diphytanoyl phosphocholine bilayers formed on moderately doped and highly doped n-type silicon using Langmuir-Blodgett-based deposition techniques. The authos demonstrate that a detailed understanding of the contributions to the impedance response is important in developing silicon-based membrane platforms. The authors further report on the bias dependence of the impedance, and show that on highly doped n-type silicon, the membrane impedance can be measured over a 2 V range.