Afterglow Nanoprobes for In-vitro Background-free Biomarker Analysis

Accurate detection of biomarkers is essential for disease diagnosis. Although the highly sensitive fluorescence probes are feasible for the above goal, it is typically interfered by the auto-fluorescence and light scattering of the biological samples. Photochemical afterglow system (consisting of photosensitizer, afterglow substrate and emitter) based on cascade photochemical reactions exhibits long-lived luminescence (seconds to hours), thus avoiding background interference. With the assistance of polymers, such as polystyrene microspheres, the photochemical afterglow systems have been transformed into homogeneous and water-soluble nanoparticles, and used for in-vitro biomarker analysis. Here, we summarized the principle, preparation and applications of these afterglow nanoparticles, and evaluated their performance in clinical sample testing by comparing with other nanoparticle-based methods. Finally, several problems and possible solutions of afterglow nanoparticle-based methods in biomarker determination were also mentioned.