Photosensitive protein patterning with electrophoretic deposition

This letter reports on the micro-patterning of the photosensitive protein of bacterioRhodopsin (bR) geared toward bioelectronics-based image sensors. bR proteins are denatured by existing micro-fabrication processes, including destructive high-temperature (>100°C) heating and organic solvent cleansing. In our process, the desired area of the electrode for immobilizing bR is defined by a hydrophobic polymer that repels bR. After micro-fabrication, bR is selectively formed on the defined areas using electrophoretic deposition. A 5-µ m patterning resolution was achieved. An 8 × 8 photosensor array was fabricated, and its output electric charge was detected.