Fig. 1
From: Plug-and-play metabolic transducers expand the chemical detection space of cell-free biosensors
A modular design workflow for engineering scalable cell-free biosensors. a Cell-free biosensors are composed of three modules: a generic sensor module linked to an output module and a metabolic transducer module transforming different molecules into ligands detectable by the sensor module. b An undetectable ligand is converted into a detectable ligand by the enzyme from the transducer module. Binding to the transcription factor controls the sensor module and downstream gene expression. c The biosensor design workflow starts with retrosynthetic pathway design using the SensiPath server19. Once the transducer and sensor modules are determined, the genes encoding enzymes, transcription factors, and target promoters driving a reporter are cloned into cell-free expression vectors. The sensor is calibrated by titrating the concentrations of each plasmid to maximize signal output and dynamic range
