Thioflavin T as luminescence biosensors for nucleic acid study and RNase A activity detection

An applicable RNase assay was constructed based on strong luminescent complex between Thioflavin T (ThT) and RNA. The emission of ThT was more sensitive to RNA than to DNA, and electrostatic interaction played an important role when ThT interacted with RNA. The ThT-RNA fluorescence system displayed high specific quenching for RNase A, which originated from the specific cleavage reaction of RNA by RNase A. The quantitative detection of RNase A was built with a rather low detection limit 2.47 x 10(-6) U/mL. Enzymatic kinetics and inhibitory experiments were conducted to demonstrate the utilities of this method in RNase A activity study and screening of enzyme inhibitors in biological samples.