Photochemical Doping of Protonic Transistors from a Cephalopod Protein

The field of bioelectronics has the potential to revolutionize both fundamental biology and personalized medicine. As such, much research effort has been devoted to the development of devices and materials that are intrinsically compatible with biological systems. Within this context, several recent studies have focused on protonic transistors from naturally occurring materials, such as squid-derived polysaccharides and proteins. Herein, we report the rational design, fabrication, and characterization of two- and three-terminal protonic devices, for which the active material consists of a protein-based proton conductor doped with a small molecular photoacid. We electrically interrogate these devices both in the absence and presence of illumination, demonstrating that an exogenous photophysical stimulus selectively enhances their electrical properties. Our findings hold significance for understanding and controlling proton transport not only in bioelectronic platforms but also across a wide range of voltage-regulated proton-conducting materials and device platforms.