Color-sensitive biosensors for imaging

Research on an artificial retina is mainly concentrated on the design of silicon based integrated circuits, where the spatial structure of the circuit and the electrical design of a pixel plays the main role. Color sensitivity has not been an issue, or it is realized by using separate filters in front of the circuit. There are only few studies concerning an artificial retina based on a biomolecular structure. In this study we describe some optically active biomolecules, which are potential materials for construction of an artificial retina. We use bacteriorhodopsin and its variants. This protein is produced by a bacterium, Halobacterium salinarium. The protein is closely related to the light sensitive molecule of human retina. The studied molecules have different wavelength properties with each other and when mounted on a polyvinylalcohol film, they produce an electric signal from optical input. We have produced a set of protein films with different wavelength properties and we report the basic characteristics of these films, referring them as basic elements of an artificial retina. The design principles of a biomolecule based artificial retina is also discussed