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.