Effective synthesis of fluorescent carbon dots and their application in controllable detection of deferasirox

As an iron chelation therapy, deferasirox (DEF) is commonly used as the primary treatment drug to prevent intracellular iron overload in patients with thalassemia who require long-term and large blood transfusions. However, due to the toxic side effects of long-term use, building a convenient and sensitive DEF detection method remains an important task. This study developed a simple and effective fluorescence detection strategy for DEF based on the coordination effect of DEF and Cu (DEF-Cu). The high quantum yield N-doped blue emission carbon dots (CDs) synthesized by a simple one-step hydrothermal method were applied as the fluorescent probe. The DEF-Cu exhibited a new absorption peak centered at 334 nm, overlapping with the absorption wavelength of CDs, resulting in an internal filtration effect (IFE) for quenching the fluorescence of CDs. The quenching degrees of CDs caused by DEF-Cu showed a good linear relationship in the range of 0.5–20 μg/mL, with a detection limit (LOD) as low as 0.12 μg/mL. The accurate detections of DEF in dispersible tablets and plasma were also achieved. This strategy not only enriched the understanding of the properties of target drugs but also provided valuable insights for designing CDs with specific luminescent properties and applying them to distinctive methods for drug analysis.