An innovative electrochemical sensor for brinzolamide detection in athletes' urine using a mercury-phen complex: a step forward in anti-doping

RSC Adv. 2024 Oct 28;14(46):34214-34227. doi: 10.1039/d4ra06591c. eCollection 2024 Oct 23.

Abstract

Brinzolamide (BRZ) is an antiglaucoma drug also used by athletes for doping purposes; therefore, it is prohibited by the World Anti-Doping Agency. Consequently, the presence of BRZ or its metabolites in athletes' urine constitutes a violation of anti-doping rules. The current work presents a novel electrochemical method that assesses the effectiveness of mercury oxide nanoparticles (HgO-NPs) and a mercuric chloride-1,10-phenanthroline complex (HgCl2-Phen complex) as sensors for BRZ analysis. A comparative analysis revealed that the synthesized HgCl2-Phen complex exhibited superior sensitivity and efficiency in determining BRZ levels. The properties of the modifiers were extensively characterized using elemental analysis, X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, and scanning electron microscopy (SEM). Furthermore, electrochemical characterization was conducted using square wave voltammetry (SWV), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The electrode showed a good response for SWV evaluations of BRZ in a concentration range of 0.1 to 6.0 μmol L-1, with very low limits of detection (0.01 μmol L-1) and quantitation (0.031 μmol L-1). The method's applicability was validated by detecting BRZ in urine samples from healthy human volunteers and in pharmaceutical eye drops. Additionally, the practical effectiveness of the method was assessed using the blue applicability grade index (BAGI). The key advantages of this sensor include its simple manufacturing process, as well as its remarkable sensitivity and selectivity.