Interaction of Cy3 dye with CCG and its application for BSA detection

Chemically converted graphene (CCG) was found to effectively quench the fluorescence emission of Cy3 dye 1 (the intensity is down to 1/38 of 1 alone) in aqueous solution, due to the formation of a CCG–1 hybrid. After the addition of a certain amount of bovine serum albumin (BSA) into the above-mentioned system, about 60 times fluorescence enhancement was observed for the hybrid CCG–1. This was employed to discriminate BSA: the fluorescence intensity was found to be proportional to the BSA added in the concentration range from 0 to 8 × 10−6 M, and the BSA detection limit was down to 5 × 10−8 M.