Optical Characteristics of Polymer Films Based on Bacteriorhodopsin for Irreversible Recording of Optical Information†

Abstract

Bacteriorhodopsin (BR)-containing polymer films have been developed in which photoinduced transformations of BR molecules take place during the process of photoinduced hydroxylaminolysis (PHA). The routine simplified scheme of the phototransformation is B <--> M(412) in the case of polymer films based on nonmodified BR. In the case of polymer films based on BR modified by hydroxylamine (HA), this scheme is changed to [formula in text] where retinal oxime (RO) is a final product of chemical trapping of retinal by the HA molecule. Under certain conditions, the rate of RO to B regeneration is infinitely low. So, the irreversibility of RO formation allows one to use PHA for the preparation of films for irreversible write once recording. Some optical sensitometric characteristics are compared for polymer-BR films and polymer-BR-HA films. It has been shown that the photosensitivity level for polymer-BR-HA films depends on the time after film preparation. A method is offered to increase the photosensitivity of polymer-BR-HA films and to avoid the photosensitivity decrease with the time after film preparation.