Cowpea‐Powered Luminescence: A Green Carbon Quantum Dots Nanosensor for Vinpocetine Determination With In Vitro Cytotoxicity Assessment Application

An innovative and eco-friendly approach was developed for estimating vinpocetine (VPO) in its pharmaceutical dosage form. The proposed method relied on using a fluorescent nanoprobe synthesized from black-eyed Cowpeas beans and thiourea via microwave irradiation within 4 min for the first time. The synthesized nitrogen and sulfur-doped carbon quantum dots (N, S-doped CQDs) demonstrated an excellent fluorescence peak at 382 nm after excitation at 320 nm. Vinpocetine's superior capability for quantitatively quenching the prepared N, S-doped CQDs' fluorescence enabled its spectrofluorimetric estimation for the first time. The proposed method showed excellent linearity over a concentration range from 5.0 to 85.0 μM with a high sensitivity level illustrated by the low values of LOD and LOQ (1.03 and 3.13 μM, respectively). The method was applied to content-uniformity testing and confirmed compliance with dosage uniformity requirements. The method met the acceptance criteria adopted by the ICH guidelines regarding the validation parameters. The cytotoxicity impact of the generated N, S-doped CQDs was investigated, and the results revealed their high biocompatibility. The environmental friendliness of the proposed method was assessed by implementing ComplexMoGAPI, AGREE, and AGSA tools, and the findings promote its future applicability and sustainability in the analytical quality control sector.