Fluorimetric determination of Vonoprazan via quenching of nitrogen and sulfur co‐doped carbon quantum dots: A rapid and sustainable analytical approach

Abstract

In this study, an environmentally sustainable fluorimetric method for determination of Vonoprazan fumarate (VON) in dosage forms using nanoprobes consisting of nitrogen and sulfur co-doped carbon quantum dots (N, S-CQDs). The N, S-CQDs were prepared through a microwave-assisted method in 30 s. The resulting N, S-CQDs were characterized using transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), Fourier transform infrared spectroscopy (FTIR), and X-ray photoelectron spectroscopy (XPS). They exhibit fluorescence emission at 460 nm after excitation at 385 nm with a high quantum yield (60%). The analytical approach for VON determination relies on the quenching effect exerted by VON on the native fluorescence intensity of CQDs. The quenching mechanism was investigated using Stern-Volmer plots. The proposed method demonstrates linearity across a concentration range 10-80 μM (4.6-36.8 μg/mL) with corresponding limits of detection and quantitation calculated as 2.17 μM (0.99 μg/mL) and 6.58 μM (3.02 μg/mL), respectively. The method has been effectively utilized for the determination of VON in the pharmaceutical samples. Statistical comparison with reported RP-HPLC has been performed to verify the accuracy and precision of the developed method. The environmental sustainability of the developed method has been thoroughly examined through various greenness metrics.