(429f) Electrogenetic Design for Bidirectional Communication at a Bioelectronics Interface

Toward bioelectronics technology, there is a compelling opportunity to integrate biological systems with electronic devices, which have become increasingly networked and ubiquitous. However, these two entities are dissimilar in composition and information processing mechanism. Biology is organically composed and often uses molecular recognition for signal response, while electronics are typically inorganic and operate by electron flow. This work presents an approach to interface genetically-programmed bacteria with electronics as a biohybrid system, addressing both challenges of physical coupling by self-assembly and communication compatibility using electrochemically-active molecular cues. First, bacteria express a peptide tailored for inorganics, which is fused to an outer membrane protein for surface display. In this way, the bacteria can selectively assemble onto an electrode surface. Then, the cells feature a simple, modular genetic circuit for electrochemically-activated gene expression. Specifically, in a voltage-dependent manner, a charged electrode biases the oxidation state of redox-active signal molecules. This, in turn, influences gene expression based on redox-specific recognition of the molecular cue. Further, the electrogenetic cells are demonstrated to provide multiple outputs in response to electrochemical stimulation. The cells serve as bioelectronic transducers by 1) relaying the voltage input as small molecule quorum sensing signals to other cell populations and 2) providing redox-active molecular feedback to the electronic infrastructure, which is again detectable through electrochemical analysis. Because the cells are positioned directly on the electrode, this electrochemical signal exchange can occur locally across the interface. This work demonstrates bioelectronic communication where redox-active molecules serve as interconvertible signals that carry electrons between electrodes and simultaneously allow for molecular recognition events within cells. The combination of voltage-mediated redox control and electrogenetic response establishes a bioelectronics dialogue. Bioelectronics connectivity with synthetic biology may yield future applications for programmable biohybrid devices with utility in ecological settings, wearable interfaces, and in vivo environments.