Capsule confined cascade reaction generating long-lasting and intensive chemiluminescence

The development of feasible, low-cost, and long-persistent chemiluminescence (CL) systems is highly desirable for enhancing detection reproducibility and accuracy. Here, we present a space-confined CL system based on the LHC@G capsules, which are prepared via a one-pot ultrasound-assisted method to co-encapsulate glucose oxidase (GOx), hemin (a peroxidase mimic), and luminol within an oil-in-water structure. The LHC@G capsules are used for producing glow-type CL emission. Specifically, glucose is catalyzed by GOx on the capsule surface, yielding H₂O₂. The H₂O₂ then diffuses into the oil core and undergoes hemin-catalyzed in situ blue emission of luminol. The LHC@G capsule-based CL system exhibits intensive and prolonged blue emission for over 1500 s, with a nearly threefold enhancement in CL intensity compared to that of luminol solution. Mechanistic studies reveal that the excellent CL performance stems from a highly efficient cascade reaction and regulated diffusion. The proposed capsule CL system exhibits excellent reproducibility and storage stability, and has been successfully developed for simple, fast, and sensitive visual glucose detection with a LOD of 1.21 μM. This work provides a convenient strategy for constructing long-persistent and accurate CL systems in the field of point-of-care testing (POCT).