Biomimetic Redox\nCapacitor To Control the Flow of\nElectrons

In biological systems, electrons, energy, and information\n“flow”\nthrough the redox modality, and we ask, does biology have redox capacitor\ncapabilities for storing electrons? We describe emerging evidence\nindicating that biological phenolic/catecholic materials possess such\nredox capacitor properties. We further describe results that show\nbiomimetic catecholic materials are reversibly redox-active with redox\npotentials in the midphysiological range and can repeatedly accept\nelectrons (from various reductants), store electrons, and donate electrons\n(to various oxidants). Importantly, catechol-containing films that\nare assembled onto electrode surfaces can enhance the flow of electrons,\nenergy, and information. Further, catechol-containing films can serve\nas redox-based interactive materials capable of actuating biological\nresponses by turning on gene expression from redox-responsive genetic\ncircuits. Looking forward, we envision that the emerging capabilities\nfor measuring dynamic redox processes and reversible redox states\nwill provide new insights into redox biology and will also catalyze\nnew technological opportunities for information processing and energy\nharvesting.