Electrochemical impedance spectroscopy for black lipid membranes fused with channel protein supported on solid-state nanopore.

Abstract

Black lipid membranes (BLMs) have been used for detecting single-channel activities of pore-forming peptides and ion channels. However, the short lifetimes and poor mechanical stability of suspended bilayers limit their applications in highthroughput electrophysiological experiments. In this work, we present a synthetic solid-state nanopore functionalized with BLM fused with channel protein. A nanopore with diameter of~180nm was electrochemically fabricated in a thin silicon membrane. Folding and painting techniques were demonstrated for production of stable suspended BLMs followed by incorporation of transmembrane protein, ENaC. Membrane formation was confirmed by employing electrochemical impedance spectroscopy (EIS) in the frequency regime of 10-2-105Hz. Results show that electrochemically fabricated solid statenanopore support resulted in excellent membrane stability, with>1GΩ ofup to 72 and 41h for painting and folding techniques, respectively. After fusion of ENaCchannel protein, the BLM exhibits thestability of ~5h. We anticipate that such a solid-state nanopore with diameter in the range of 150-200nm and thickness<1µm could be a potential platform to enhance the throughput of ion-channel characterization using BLMs.