Carbon Nanodots as a Red Emissive Fluorescent Probe for the Super‐Resolution Microscopy of DNA Dynamics during Paclitaxel Treatment

Paclitaxel is a commonly used frontline chemotherapeutic drug for cancer treatment. It is known to be functional by arresting the microtubule disassembly during mitosis. Recently, a nonmitotic pathway has been evolving and thus contemplating the mitotic mechanism. Herein, using super‐resolution microscopy (SRM), the nuclear dynamics is directly visualized and the mechanism of paclitaxel treatment is unveiled. A new class of nontoxic, biocompatible, and highly fluorescent carbon nanodots (CNDs) are used as a fluorescent probe that are highly capable to directly stain the nuclear DNA and capture the SRM imaging of chromosomes and the chromatin structures. Apart from SRM imaging of chromosomes during all stages of normal mitotic cell division, CNDs successfully visualize the formation of lagging, mis‐segregated, and bridging chromosomes, leading to the multi‐micronucleus formation upon paclitaxel treatment. A detailed chromatin remodeling analysis suggests that heterochromatin plays an important role in the formation of condensed multi‐micronucleus, ultimately leading to cell death.