College of Chemistry, Chemical Engineering and Materials Science, Collaborative Innovation Center of Functionalized Probes for Chemical Imaging in Universities of Shandong, Key Laboratory of Molecular and Nano Probes, Ministry of Education, Shandong Provincial Key Laboratory of Clean Production of Fine Chemicals, Shandong Normal University, Jinan 250014, China. [Email]
We develop a simple fluorescence method for the sensitive detection of cathepsin B activity based on the integration of a peptide-DNA conjugate with multiple cyclic signal amplification. This method can detect cathepsin B activity with an extremely low detection limit of 8.1 × 10-12 g mL-1 and a large dynamic range of 4 orders of magnitude from 1 × 10-11 to 1 × 10-7 g mL-1, and it can even measure cathepsin B activity at the single-cell level. This method can be further used for the screening of cathepsin B inhibitors.