SULFUR QUANTUM DOTS AS A MULTIFUNCTIONAL FLUORESCENT NANO SENSOR FOR RAPID ANTIBIOTIC DETECTION AND ANTICANCER ACTIVITY AGAINST HUMAN COLON CANCER CELL LINES

In the present study, sulfur quantum dots (SQDs) were successfully synthesized by a microwave-assisted method using PEG6000 as the precursor material. The synthesized SQDs were characterized using UV–Visible spectroscopy, fluorescence spectroscopy, X-ray diffraction (XRD), transmission  electron  microscopy  (TEM),  and  Raman spectroscopy, which confirmed the formation of stable, fluorescent, quasi-spherical nanoparticles with nanoscale dimensions. The optical studies demonstrated strong fluorescence emission and effective “switch-on” fluorescence behavior, indicating the suitability of SQDs for bioimaging applications. The biological activity of the synthesized SQDs was evaluated against Caco-2 cancer cell lines through MTT assay,reactive oxygen species (ROS) analysis, cellular uptake studies, confocal laser scanning microscopy (CLSM), apoptosis assay, and cell cycle analysis. The results revealed that SQDs exhibited significant concentration-dependent cytotoxicity and effectively reduced the viability of Caco-2 cells. Enhanced intracellular uptake and fluorescence imaging confirmed efficient penetration of SQDs into cancer cells. Further studies demonstrated that SQDs induced oxidative stress-mediated apoptosis and cell cycle arrest, thereby contributing to their anticancer activity. Overall, the synthesized SQDs showed excellent optical properties along with promising in vitro anticancer potential against Caco-2 cancer cells, suggesting their possible application as fluorescent nanomaterials for cancer diagnosis, bioimaging, and therapeutic purposes.

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