Integration of a peptide–DNA conjugate with multiple cyclic signal amplification for the ultrasensitive detection of cathepsin B activity†
Abstract
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.