Control of pH in bioelectronics and applications

Ions and biomolecules are the languages that biological systems use to transfer signals in intracellular communication and organism function. As such, bioelectronic devices that conduct ions and biomolecules rather than electrons and holes are particularly suited for biological integration. Among these ions, protons (H+) are important in many biochemical reactions including neuronal excitability and oxidative phosphorylation of adenosine triphosphate (ATP). In this Research Update, we describe our efforts in measuring and controlling the concentration of H+ ions in biological systems using bioelectronic devices with contacts that are made of palladium and palladium hydride (Pd/PdHx). Pd/PdHx contacts act as an electron to proton transducer and can be used in artificial membranes containing ion channels, biohybrid photodetectors, the delivery of biochemical stimuli, pH sensitive glucose sensing, and precise control of pH using machine learning.