<p>Histidine-derived carbon dots (His-CDs) were synthesized to detect staurosporine-induced apoptosis in T lymphoma (Jurkat) cells. The His-CDs were characterized for their physical and chemical properties including size, morphology, fluorescence, and surface functionality. Transmission electron microscopy (TEM) revealed a spherical morphology with an average size of 11.4 ± 3.4 nm. Fluorescence analysis showed maximum excitation at 338 nm and emission at 415 nm, attributed to the carbon dots’ quantum confinement effect and surface defects. FTIR and SEM–EDS confirmed the presence of hydroxyl, amine, aromatic rings, and alkyl (C-H) functional groups and carbon, nitrogen, and oxygen elemental composition in ratios of 52%, 24.8%, and 23.3%, respectively. His-CDs were evaluated for cytotoxicity and apoptosis detection in Jurkat cells. Fluorescence microscopy and flow cytometry analysis demonstrated concentration-dependent fluorescence, suggesting effective cellular uptake of His-CDs. The apoptotic-sensing capability of His-CDs was tested using staurosporine, an apoptosis inducer. A concentration-dependent increase in fluorescence was observed with increasing staurosporine concentrations, indicating the His-CDs’ sensitivity to apoptosis. The time-dependent fluorescence increases were noted with prolonged staurosporine exposure. Z-DEVD-FMK, a caspase-3 inhibitor, confirmed that the apoptosis detected by His-CDs was caspase-3 dependent, as co-treatment reduced His-CDs’ fluorescence in the cell. In conclusion, these results demonstrate that His-CDs are biocompatible, sensitive apoptosis sensors and hold the potential for monitoring apoptotic pathways in cellular systems.&#xa0;</p> Graphical Abstract <p></p>