A single repressor for multi-purpose biosensing applications through regulating various types of catalytic reaction strategies

Repressors can be used as signal switch to develop useful biosensors for metabolite detections. Whether different DNA reactions can be regulated by a single repressor to achieve various biosensing purposes has remained to be explored. Here, we used GalR (Gal repressor) as a model to verify its ability to control six DNA reactions, and chose SDA (strand displacement amplification) and RE (restriction endonuclease) reactions to achieve three biosensing purposes. Firstly, both SDA and RE reactions regulated by GalR can detect D-galactose effectively. Secondly, lactase was successfully employed to expand the platforms for lactose detecting. Thirdly, we used these platforms to achieve inhibitor screening. Our results demonstrated that a single repressor has the potential to effectively regulate different catalytic reactions and to be fully exploited for various biosensing purposes.