A red-NIR emissive probe for the selective detection of albumin in urine samples and live cells.

A dicyanomethylene-4H-chromene-derived turn-on fluorescence probe (TG-SA) has been designed and synthesised for the selective detection of human serum albumin (HSA). TG-SA exhibits good photostability and selective red-near infrared (NIR) fluorescence enhancement in the presence of HSA in complex samples containing numerous biological analytes. The probe predominantly binds domain II of HSA that accounts for the observed selective fluorescence enhancement. The red-NIR fluorescence probe TG-SA can be effectively used for staining HSA/SA in gel electrophoresis, quantification and validation of HSA in clinical urine samples and monitoring serum albumin in live cells.