Molecular Switching in Phospholipid and Azobenzene Mixed Monolayers Using Maxwell-Displacement-Current-Measuring Technique

Abstract

Molecular switching in phospholipid and azobenzene mixed monolayers was examined by Maxwell-displacement-current (MDC) measurement in combination with the surface pressure measurement. It was found that the molecular aggregation of pure azobenzene monolayers was reduced by the introduction of phospholipids possessing unsaturated long alkyl chains (DOLPC) or saturated long alkyl chains (D-DPPC). The surface pressure change was detected from mixed monolayers over the entire range of molecular area with alternating irradiation of ultraviolet and visible light. On the one hand, MDC was generated from DOLPC-azobenzene mixed monolayers over the entire range of the molecular area, whereas the generation of MDC from D-DPPC-azobenzene mixed monolayers was limited in the molecular area. We discussed the generation of MDC from phospholipids-azobenzene mixed monolayers in combination with the surface pressure change measurement.