Photochemical Switching of Electrochemical Process by Spiropyran LB Films

Photoelectrochemical control of the ion-blocking ability of the Langmuir–Blodgett (LB) film as an ion gate was demonstrated on a gold optically semi-transparent electrode (Au OTE) coated with multilayers containing photoresponsive amphiphilic compounds. When UV light was irradiated upon the modified Au OTE, this LB film became more compact to block permeation of ions into and out of the LB film and therefore inhibited electrochemical reactions of the redox active species in solution. On the other hand, when visible light was irradiated, this layer became more loose and redox species could penetrate the LB film.