Nitrogen and sulfur-doped carbon quantum dots as fluorescent nanoprobes for spectrofluorimetric determination of olanzapine and diazepam in biological fluids and dosage forms: application to content uniformity testing

• Published in: BMC chemistry 2022-11, Vol.16 (1), p.98-98, Article 98
• Main Authors: Magdy, Galal, Said, Noura, El-Domany, Ramadan A., Belal, Fathalla
• Format: Article
• Language: English
• Subjects: Antipsychotics; Benzodiazepines; Blood plasma; Carbon; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Citric acid; Content uniformity; Diazepam; Drugs; Fluorescence; Fluorescence quenching; Nitrogen; Nitrogen, sulfur-doped carbon quantum dots; Olanzapine; Quantum dots; Quenching; Selectivity; Spectrofluorimetry; Sulfur; Sulfur compounds; Tablets
• ISSN: 2661-801X; 2661-801X
• DOI: 10.1186/s13065-022-00894-y

A validated, sensitive, and simple spectrofluorimetric method was developed for the analysis of two important CNS-acting drugs, olanzapine and diazepam, in their commercial tablets without the need for any pretreatment steps. The developed method relied on the quantitative quenching effect of each of olanzapine and diazepam on the native fluorescence of nitrogen and sulfur-doped carbon quantum dots (NS@CQDs). NS@CQDs were prepared from thiosemicarbazide and citric acid by a facile one-pot hydrothermal technique. The synthesized NS@CQDs were characterized by different spectroscopic and microscopic techniques. NS@CQDs produced a maximum emission peak at 430 nm using 360 nm as an excitation wavelength. Calibration curves showed a good linear regression over the range of 5.0–200.0 and 1.0–100.0 μM with detection limits of 0.68 and 0.29 μM for olanzapine and diazepam, respectively. The adopted method was used for the determination of the investigated drugs in their tablets with high % recoveries (98.84–101.70%) and low % RSD values (