A protonic biotransducer controlling mitochondrial ATP synthesis.

In nature, protons (H+) play an important role in biological activities such as in mitochondrial ATP synthesis, which is driven by a H+ gradient across the inner membrane, or in the activation of acid sensing ion channels in neuron cells. Bioprotonic devices directly interface with the H+ concentration (pH) to facilitate engineered interactions with these biochemical processes. Here we develop a H+ biotransducer that changes the pH in a mitochondrial matrix by controlling the flow of H+ between a conductive polymer of sulfonated polyaniline and solution. We have successfully modulated the rate of ATP synthesis in mitochondria by altering the solution pH. Our H+ biotransducer provides a new way to monitor and modulate pH dependent biological functions at the interface between the electronic devices and biological materials.