Electronic control of H⁺ current in a bioprotonic device with Gramicidin A and Alamethicin.

Abstract

In biological systems, intercellular communication is mediated by membrane proteins and ion channels that regulate traffic of ions and small molecules across cell membranes. A bioelectronic device with ion channels that control ionic flow across a supported lipid bilayer (SLB) should therefore be ideal for interfacing with biological systems. Here, we demonstrate a biotic-abiotic bioprotonic device with Pd contacts that regulates proton (H⁺) flow across an SLB incorporating the ion channels Gramicidin A (gA) and Alamethicin (ALM). We model the device characteristics using the Goldman-Hodgkin-Katz (GHK) solution to the Nernst-Planck equation for transport across the membrane. We derive the permeability for an SLB integrating gA and ALM and demonstrate pH control as a function of applied voltage and membrane permeability. This work opens the door to integrating more complex H⁺ channels at the Pd contact interface to produce responsive biotic-abiotic devices with increased functionality.