Fluorescence‐Based Detection of Furosemide in Pharmaceutical Products Using Synthesized Carbon Nanoparticles

Accurate dosing, therapeutic efficacy, patient safety, and quality control in pharmaceuticals depend on precise drug concentration monitoring. This study presents a novel fluorescent detection method employing fluorescent carbon nanoparticles (CNPs) for quantifying furosemide in pharmaceutical formulations. CNPs were synthesized via a simple one‐step hydrothermal process using N,N′‐methylenebisacrylamide (N,N‐MBA) as a precursor. Characterization by TEM, FTIR, UV–vis spectroscopy, particle size analysis, and EDX confirmed their successful formation. The synthesized CNPs exhibited strong and stable fluorescence with a quantum yield of 25.87%. Upon addition of furosemide in phosphate buffer (pH 6.5), fluorescence quenching occurred at an excitation wavelength of 320 nm and emission at 395 nm. The method displayed a linear response between fluorescence intensity and furosemide concentration (2.0–30 µg/mL) with a detection limit of 0.5 µg/mL and correlation coefficient ( R 2 ) of 0.9979. It also demonstrated excellent selectivity in the presence of common excipients. Validation confirmed high accuracy and precision. These findings highlight the potential of CNPs as a robust and sensitive platform for quality control of furosemide in pharmaceutical products.