A green method for the preparation of carbon quantum dots from yellow lupin peel waste for spectrofluorometric determination of nirmatrelvir.

The COVID-19 pandemic has highlighted the urgent need for effective antiviral agents. One such promising drug is nirmatrelvir (NIRMA), which has demonstrated the ability to inhibit viral replication and reduce hospitalization and mortality rates. In the field of analytical chemistry, carbon quantum dots (CQDs) derived from fruit peel waste have gained attention for their eco-friendly and cost-effective properties. In this study, CQDs were synthesized from the peel biomass waste of yellow lupin and utilized for the spectrofluorometric determination of NIRMA in pharmaceutical tablets. The proposed method offers simplicity and speed compared to existing methods. The synthesis process involved washing and grinding the peel waste, followed by heating in propylene glycol and purification using a dialysis membrane. The resulting CQD solution showed fluorescence at an emission wavelength of 411 nm upon excitation at 325 nm. The validation of the method, including linearity, range, limit of detection and quantification, accuracy, precision, and robustness, was conducted following ICH guidelines. The fluorescence intensities exhibited a linear relationship with increasing NIRMA concentration in the range of 15-150 µg/mL. The limit of detection found to be 4.0 μg/mL, with %relative standard deviations ≤ 1.46. This spectrofluorometric method represents a novel approach for the determination of NIRMA using CQDs derived from yellow lupin peel waste.