CHARACTERIZATION OF THE PREPARATION PROCESS AND THE PHOTOCHEMICAL CONTROL OF ELECTRICAL-PROPERTIES OF BILAYER LIPID-MEMBRANES CONTAINING AZOBENZENE CHROMOPHORES

We prepared photoresponsive bilayer lipid membranes (BLMs) containing azobenzene derivatives (4'-octylazobenzene-4-oxybutyric acid (AZ)) and observed the rapid and reversible changes in their electrical properties when irradiated with light. The BLMs consist of AZ (8 mol%) and glyceryl monooleate. The changes in capacitance and conductance upon irradiation by light were found to be 10 and 20%, respectively. The changes in the electrical properties of the membrane and in the structure of AZ under light irradiation were analyzed simultaneously by in-situ spectroscopic, electrical and microscopic measurements. These measurements showed that the electrical changes induced by exposure to light resulted from reversible changes in the membrane structure initiated by the photoisomerization reaction of AZ. This structural change in the membrane occurred within 1 s.