Superbright organosilica nanodots as a universal sensor for fast discrimination and accurate quantification of live/dead cells

Abstract

Rapid and quantitative discrimination between live and dead cells is highly desirable yet remains a challenging task. Here, we report the use of the ultrabright green-emitting organosilica nanodots (OSiNDs, photoluminescence quantum yield: ˜100%) for fast (1 min in vitro and 5 min in vivo), wash-free, and universal labeling of the dead bacterial, fungal, and mammalian cells, which meets the demand of the green fluorescent probes that can specifically image the dead cells. The photostability of OSiNDs surpasses that of the commercial dyes, such as propidium iodide (PI) and SYTOX Green nucleic acid stain (SYTOX), making OSiNDs more suitable for long-term and stable monitoring of the cell viability. With the assistance of a commercial red fluorescent dye SYTO 60, we develop an in situ method for rapid and accurate quantification of live/dead cells. Motivated by the unique optical advantages and high sensitivity of OSiNDs to the cell viability, the OSiNDs are employed to observe the in vivo cellular changes induced by doxorubicin using zebrafish as a model, demonstrating their great potential for evaluating the toxicity/efficacy of the therapeutic agents in real time. Owing to the excellent biocompatibility and low cost, the OSiNDs can be a universal probe for efficient and accurate differentiation and quantification of the live and dead cells, which may find wide applications in the biomedical field.