Fluorescence Analysis of Propranolol Hydrochloride Using Mercaptoacetic Acid‐Capped Cadmium Sulfide Quantum Dots and Mechanism of Reaction Process

ABSTRACT

Propranolol hydrochloride (PRO‐HCl), a nonselective β ‐adrenergic receptor blocker, is widely utilized in the treatment of various medical conditions including hypertension, angina pectoris, cardiac arrhythmias, migraine prophylaxis, and certain anxiety disorders. In this study, we developed a simple, convenient, and sensitive quantitative detection method for PRO‐HCl in aqueous environments, based on the fluorescence generated from the reaction between Cadmium sulfide quantum dots (CdS QDs) and PRO‐HCl at room temperature. The synthesized CdS QDs were thoroughly characterized using fluorescence spectroscopy, UV–Vis spectrophotometry, and Fourier‐transform infrared spectroscopy (FTIR) to investigate their optical and structural properties. Our experimental results demonstrated a significant enhancement in the fluorescence intensity of CdS QDs in the presence of low concentrations of propranolol hydrochloride. Through systematic optimization of experimental conditions, we established a linear relationship between the fluorescence intensity of CdS QDs and PRO‐HCl concentration within the range of 0.002–8 mg·L ⁻¹ . The linear regression equation was determined to be Y  = 0.6479 X  + 0.0685 with a correlation coefficient ( R ² ) of 0.9858, and the detection limit was found to be 0.002 mg·L ⁻¹ . Furthermore, we investigated the potential reaction mechanism between CdS QDs and PRO‐HCl. To validate the practical application of CdS QDs, the proposed method was successfully employed for the determination of PRO‐HCl in spiked environmental water samples, demonstrating the effectiveness and reliability of the CdS QDs‐based detection system.