Programmable receptors enable bacterial biosensors to detect pathological biomarkers in clinical samples

Bacterial biosensors are promising diagnostic tools, but lack scalable programming frameworks. This study introduces a modular synthetic receptor platform, EMeRALD, for engineering bacterial biosensors. EMeRALD enables the assembly of sensing modules onto a high-performance signaling scaffold in *E. coli*. The researchers successfully detected bile salts, a liver dysfunction biomarker, using sensing modules from enteropathogenic *Vibrio* species, improving sensitivity through directed evolution. A colorimetric biosensor detected pathological bile salt levels in post-liver transplant patient serum, with naked-eye detectable output. EMeRALD facilitates exploring natural sensing modules and rapidly engineering synthetic receptors for various applications.

Hung-Ju Chang, Ana Zúñiga, Ismael Conejero, Peter L. Voyvodic, Jerome Gracy, Elena Fajardo-Ruiz, Martin Cohen-Gonsaud, Guillaume Cambray, Georges-Philippe Pageaux, Magdalena Meszaros, Lucy Meunier, Jerome Bonnet