Photochemical Switching of Ion Transport Through ‘Quasi-Channels’ Incorporated into Black Lipid Membrane

Abstract

We fabricated the black lipid membrane (BLM) of soybean lecithin doped with spiropyran derivatives. When a positive DC voltage was applied on the BLM, the membrane current changed under alternate irradiation with ultraviolet light and visible light. The change in the membrane conductivity due to photoisomerization is responsible to the change in the ion permeability across the membrane. The photoresponsive BLM cell exhibited nonsymmetric current-voltage characteristics, which suggest the localization of spiropyran molecules on one side of the membrane.