Tunable afterglow via confined photocatalytic chemiluminescence for biosensing applications.

Long-lived afterglow materials are valuable for biological applications due to their ability to minimize autofluorescence interference, yet existing systems often require complex mechanisms and precise compositions. Here we present a universal afterglow platform achieved by cascading photocatalytic reactive oxygen species generation and chemiluminescent reactions within spatially confined nanostructures. This approach enables facile tuning of optical properties including excitation/emission wavelengths, lifetime and intensity by adjusting the combinations and ratios of photocatalysts and chemiluminescent reagents as well as the irradiation time. As a demonstration, a stable turn-on biosensor for alkaline phosphatase activity was developed, exhibiting long-lasting afterglow in a flashing mode with high sensitivity. This versatile strategy simplifies afterglow material design and synthesis, offering customizable optical features and promising applications in biosensing and bioimaging.