Electric Field Induced Biomimetic Transmembrane Electron Transport using Carbon Nanotube Porins as Bipolar Electrodes

Cells modulate their homeostasis through the control of redox reactions via transmembrane electron transport systems. These are largely mediated via oxidoreductase enzymes. Their use in biology has been linked to a host of systems including reprogramming for energy requirements in cancer. Consequently, our ability to modulate membrane redox systems may give rise to opportunities to modulate underlying biology. The current work aimed to develop a wireless bipolar electrochemical approach to form on-demand electron transfer across biological membranes. To achieve this goal, we show that using membrane inserted carbon nanotube porins that can act as bipolar nanoelectrodes, we could control electron flow with externally applied electric fields across membranes. Before this work, bipolar electrochemistry has been thought to require high applied voltages not compatible with biological systems. We show that bipolar electrochemical reaction via gold reduction at the nanotubes could be modulated at low cell-friendly voltages, providing an opportunity to use bipolar electrodes to control electron flux across membranes. Our observations present a new opportunity to use bipolar electrodes to alter cell behavior via wireless control of membrane electron transfer.