Bioprotonics: Memories, Transistors, and pH Modulators

Abstract

Protons (H+) play an important role in controlling cell function and metabolic processes in biological systems. H+ current affects a broad range of biological activities, from ATP synthesis in mitochondria[1] to neuron signaling in the brain.[2, 3] Being able to control H+ transfer with artificial devices would provide new opportunities to study the effect of H+ on biological functions. This understanding will be vital in the development of novel therapies and sensors based on proton flux. This thesis focuses on controlling H+ transfer in biopolymers with artificial devices. I first study the dynamics of palladium hydride (PdHx) as H+ injecting contacts and its use in protonic conducting devices. Two terminal devices with PdHx contacts display memory behavior. With PdHx as contacts, a polysaccharide integrated field effect transistor measures and modulates the flow of H+. By changing the gate voltage, this H+ conducting channel can be turned on or off. In analogous to semiconductors, a proton semi-conductor model is developed to describe H+ conduction. At last, I look at the applications of such H+ conducting devices for pH modulation in solution.