ABSTRACT Temozolomide (TMZ) is an important chemotherapeutic drug, yet its weak native fluorescence hinders direct spectrofluorimetric analysis. Conventional analytical methods are often costly, labor‐intensive, and environmentally unfriendly. To overcome these limitations, a novel, eco‐friendly spectrofluorimetric method was developed using sulfur and nitrogen co‐doped carbon quantum dots (S,N‐CQDs) as fluorescent nano‐sensors. The nanodots were synthesized via a simple, one‐pot microwave‐assisted route from natural sources ( Colocasia esculenta root and chicken tissue) serving as carbon, sulfur, and nitrogen precursors. The S,N‐CQDs exhibited strong blue fluorescence, high stability, and excellent biocompatibility. TMZ induced a selective, concentration‐dependent quenching effect, enabling sensitive determination over 0.2–17.0 μg/mL with a detection limit of 0.016 μg/mL. The quenching was visually detectable under UV light and captured using a smartphone camera, allowing a simple, low‐cost detection strategy. Validation following ICH Q2 (R2) guidelines confirmed high accuracy (98.00%–101.50% recoveries), precision (RSD ≤ 1.840), and robustness (%RSD ≤ 1.771). Greenness and blueness assessments demonstrated the method's sustainability and practicality. Moreover, the S,N‐CQDs enabled intracellular imaging and real‐time monitoring of TMZ in cancer cells. This represents the first eco‐friendly CQD‐based spectrofluorimetric method for TMZ, offering a rapid, sustainable, and dual‐function platform for drug analysis and cancer research.
Magdy et al. (Sun,) studied this question.