Porous Core/Shell CoOOH Nanozymes-Enabled Glow-Type Chemiluminescence Coupled with ZIF-8@Fluorescein for Ratiometric Detection of Organophosphorus Pesticides

Classical luminol–H 2 O 2 chemiluminescence (CL) systems exhibit notable limitations for point-of-care (POC) detection, including weak luminescence intensity and short emission duration as well as insufficient selectivity for the detection of non-redox-active analytes. In the work described herein, we employed porous core/shell cobalt oxyhydroxide nanozymes to develop a novel glow-type CL system (porous core/shell CoOOH nanozyme–luminol–H 2 O 2 ) with strong and long-lasting visual luminescence. Featuring highly exposed active sites, the nanozyme’s porous core/shell structure regulates reactive oxygen species generation kinetics, enabling stable and continuous conversion of H 2 O 2 to singlet oxygen ( 1 O 2 ), hydroxyl radical ( • OH), and superoxide radical ( • O 2 – ). The stably released 1 O 2 reacts with luminol to yield a strong visible CL signal, with sustained luminescence persisting for 5 to 30 min (signal decay