Near-infrared chemiluminescent probes for monitoring leucine aminopeptidase activity

Abstract

Near-infrared (NIR) chemiluminescent probes offer high sensitivity for biological sensing applications. Herein, we present two NIR chemiluminescent probes for leucine aminopeptidase (LAP) detection, designed by covalently linking the dicyanomethylene-4H-pyran (DCM) fluorophore to Schaap's dioxetane scaffold. The impact of substitution position on chemiluminescence kinetics and enzymatic responsiveness revealed that only the para-substituted probe with minimal steric hindrance enables efficient in vitro and in vivo imaging of LAP activity.