Abstract
Protein location and interaction in the cells are important, which involve many biological processes, such as growth, metabolism and reproduction. Traditional protein detection methods have to undergo operation complex steps, therefore small molecule fluorescent turn-on probes are getting more attention due to their high sensitive, simple operation, and high specific detection with high signal-to-background ratios. Until now, the design of fluorescence probes for non-enzymatic proteins remains a challenging task. Here we introduce a general design to construct florescence probes by using conjugates of a fluorescent molecular rotor and protein specific ligands, for the selective fluorescence turn-on detection of proteins through non-enzymatic process. When the probe bind to the target proten, because of stupendous steric effect caused by the large protein volume, the fluorescence quench mechanism will be restricted, and highly fluorescence can be observed. We successfully established a TO type model for specific detection of hCAII, thrombin and avidin with fluorescent turn-on ratios up to 90-fold. We also demonstrated that one of the fluorescent probes can be employed to visualize carbonic anhydrase expressed on the cell surface, as well as sulfa drugs detection.