Electrochemical Interfaces for Gene Circuit-Based Sensors

The engineered assembly of synthetic gene networks has created a wide range of function in biological systems. Reporter output from these networks has primarily been optical (e.g. fluorescent, colorimetric), which has limited the potential to measure multiple distinct signals. We have developed an electrochemical interface that permits multiplexed detection for cell-free synthetic gene networks. We have engineered a scalable system of reporter enzymes that liberate DNA strands in solution, which results in an electrochemical signal when these newly cleaved sequences hybridize at the surface of a nanostructured microelectrode. We describe the development of this interface and show its utility using a ligand-inducible gene circuit and toehold switch-based sensors, including the detection of multiple antibiotic resistance genes in parallel. This technology has the potential to expand synthetic biology by providing an interface with materials, hardware and software.