Ultraviolet protection using intensity-dependent spectral shift in bacteriorhodopsin

The optical absorption properties of biological protein bacteriorhodopsin (bR) under the illumination of different intensity and pH environment were investigated. It is observed that the wild type bR film offers more than 30% effective UV protection. The UV protection effect can be further enhanced to 90% in some specific UV region by genetically or chemically modifying bR molecules or by the illumination of visible wavelengths ranging from green to red wavelengths. Preliminary results indicate that bR could be a promising material for UV protection.