Greatly enhanced detection of a volatile ligand at femtomolar levels using bioluminescence resonance energy transfer (BRET)

Here, we report the creation of a novel chimaeric BRET-based biosensor by insertion of sequences encoding a bioluminescent donor and a fluorescent acceptor protein into the primary sequence of a GPCR. The BRET2-ODR-10 biosensor was expressed in membranes of Saccharomyces cerevisiae. Assays conducted on isolated membranes indicated an EC50 in the femtomolar range for diacetyl. The response was ligand-specific and was abolished by a single point mutation in the receptor sequence. Novel BRET-GPCR biosensors of this type have potential application in many fields including explosive detection, quality control of food and beverage production, clinical diagnosis and drug discovery.