Abstract: Caspase-3 is a very important protease in cell apoptosis and plays a crucial role in many diseases. A new probe Ac-Asp-Glu-Val-Asp-Cys(StBu)-Lys(FITC)-CBT (1) was reported, which can be reduced by TCEP and cleaved by caspase-3 to yield the amphiphilic dimer (1-D).1-D can quickly self-assemble into nanoparticles to induce a clear fluorescence quenching effect because of the aggregation-caused quench. The nanoparticles were characterized by means of dynamic light scattering (DLS), transmission electron microscope (TEM), and high performance liquid chromatography (HPLC). As a result, the fluorescence intensity has a linear correlation with the concentration of caspase-3, which could be applied to sensing caspase-3 activity in vivo in the future.

Key words: caspase-3, nanoparticle, fluorescence quenching effect