Quality by design-aided acid-free synthesis of self P, N, S-doped black seed-derived carbon quantum dots for application as a nanosensor for eltrombopag environmental and bioanalysis and pharmacokinetic assay.

ABSTRACT

Herein, we developed a rapid, one-step, and cost-effective methodology based on the fabrication of water-soluble self-nitrogen, sulfur, and phosphorus co-doped black seed carbon quantum dots (BSQDs) via microwaveirradiation in six minutes. Our synthesis approach is superior to those in the literature as they involved long-time heating (12 h) with sulfuric acid and sodium hydroxide and/or high temperatures (200 °C). A full factorial design was applied to obtain the most efficient synthesis conditions.BSQDs displayed excitation-independent emissions, demonstrating the purity of the synthesized BSQDs, with a maximum fluorescence at 425 nm after excitation at 310 nm. Eltrombopag olamine is an anti-thrombocytopenia drug that is also reported to cause toxicity in river water based on its Persistence, Bioaccumulation, and Toxicity (PBT). The synthesized BSQDs were employed as the first fluorometric sensor for environmental and bioanalysis of eltrombopag. The fluorescence of BSQDs decreased with increasing concentrations of eltrombopag, with excellent selectivity and sensitivity down to 30 ppb. BSQDs were successfully applied as sensing probes for the detection of eltrombopag in medical tablets, spiked and real human plasma samples, and river water samples, with an overall recovery of at least 97 %. The good tolerance to high levels of foreign components and co-administered drugs indicates good selectivity and versatility of the proposed methodology. Plasma pharmacokinetic parameters such as t1/2, Cmax, and t max of eltrombopag were evaluated to be 9.91 h, 16.0 µg mL-1, and 5 h, respectively. Moreover, the green character of the BSQDs as a sensor was proved by various analytical greenness scales.