Colloquium: Engineering Biohybrid Systems for Bioelectrical Communication and Sustainable Synthesis

ABSTRACT

Biohybrid systems, which merge the molecular precision of synthetic materials with the adaptive, self-regenerating capabilities of living organisms, offer a compelling platform for addressing fundamental challenges in energy, sensing, and manufacturing. This talk will explore our efforts to engineer these systems by manipulating charge transport and catalytic processes at the interface between living cells and functional materials.

First, we address the challenge of real-time environmental monitoring by designing bio-electronic interfaces that transduce biochemical recognition events into electrical signals. Traditional biosensors are often limited by the slow reaction-diffusion kinetics of protein synthesis. We overcome this by engineering bacteria with a synthetic, modular electron transport chain, effectively creating a programmable, self-replicating micro-reactor that generates a direct amperometric current. By encapsulating these engineered cells within a matrix of conductive nanomaterials, we enhance charge extraction and achieve mass-transport-limited detection of target analytes in minutes. This work establishes design principles for creating a new class of low-power, field-deployable bioelectronic sensors by controlling charge carrier dynamics across the biotic-abiotic interface.

Second, we harness the catalytic machinery of biohybrid systems for sustainable synthesis, focusing on the thermodynamically challenging conversion of CO₂ into valuable multicarbon products using solar energy. We have developed a tandem catalytic strategy that couples a semiconductor-molecular hybrid photocatalyst for light harvesting and CO₂ reduction to syngas (CO/H₂), with an evolved bacterium that ferments this syngas into C₂ products like acetate and ethanol. This approach leverages a solid-state system for efficient energy capture and a self-assembling biological system for highly specific, room-temperature C-C bond formation—a significant departure from energy-intensive industrial processes. Through directed evolution, we dramatically enhanced the organism's metabolic flux, an optimization confirmed via isotopic labelling that traces the atomic pathways from gaseous CO₂ to liquid fuel. Ultimately, this work demonstrates how principles of energy transduction and self-organization can be used to construct integrated systems that upcycle waste carbon into functional materials powered solely by light.

BIOGRAPHY

Dr. Lin SU is a research group leader and Lecturer in Engineering Biology at Queen Mary University of London. His research focuses on engineering electron transfer at the microbe-material interface to develop next-generation bioelectronics and artificial photosynthesis. Dr. SU earned his PhD in Biomedical Engineering from Southeast University, with joint-PhD research as a visiting student at Lawrence Berkeley National Laboratory and Rice University. He later joined the University of Cambridge as a Postdoctoral Research Associate, where he was awarded a Leverhulme Early Career Fellowship and elected a Fellow of Lucy Cavendish College.