Searching for natural alternatives to replace environmentally harmful chemical reagents in analysis is just as crucial as finding easily accessible analytical tools. To reinforce these concepts, this study proposes a simple spectrofluorometric approach using natural carbon quantum dots (n-CQDs) as fluorescence probes for sensitive and environmentally friendly measurement of molnupiravir, an antiviral drug that was initially developed for influenza and has demonstrated potential efficacy against COVID-19. n-CQDs were synthesized using garlic peels (GP), a waste material, via a microwave-assisted method. n-CQDs have a characteristic broad absorbance and narrow emission spectrum, making it easier to analyze several targets. The GP-based n-CQDs showed maximum excitation/emission at 265/347 nm with an acceptable quantum yield. After reaction with molnupiravir, the produced n-CQDs demonstrated unique features to determine the tested analyte. Different factors influencing the synthesis of n-CQDs and their interaction with the studied drug, molnupiravir, were investigated and optimized. Using GP-based n-QCDs as fluorescent probe for measuring molnupiravir by FL, a green analytical approach based on the probes' fluorescence quenching was developed (GP- n-CQDs -QN-FL). The method demonstrated good linearity from 0.5 to 30 μg/mL and detection/quantitation limits of 0.19/0.5 μg/mL. Validation studies confirmed accuracy (98-102% recovery), precision (<2% RSD), robustness and selectivity. Various assessment indexes have been utilized to assess the environmental friendliness and suitability aspects of the suggested approach in comparison to other existing techniques. Furthermore, n-CQDs were successfully employed for the precise analysis of molnupiravir in its pharmaceutical capsules. The comprehensive results proved that the method can be deemed eco-friendly and feasible more than the other techniques for its intended purpose for molnupiravir determination in pharmaceutical dosage forms with an average recovery 101.17%.
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