SADIK CENOLLI, MAJLINDA VASJARI, ALMA SHEHU, NEVILA BROLI, ANA AMEDA, LUEDA KULLA, BESNIK BARAJ
Abstract
The presence of antibiotic residues in aquatic environments has become a growing environmental and public health concern due to their persistence, potential ecological impacts, and contribution to the development of antimicrobial resistance. Continuous monitoring of these emerging contaminants requires analytical methods that are sensitive, selective, and cost-effective. Although conventional techniques such as liquid chromatography–mass spectrometry (LC–MS) and gas chromatography (GC) offer high sensitivity and accuracy, their application is often limited by high operational costs, complex sample preparation, and lengthy analysis times. In contrast, electrochemical methods have attracted considerable interest because of their simplicity, rapid response, low cost, and potential for portable and in situ applications. In this study, an electrochemical sensor based on a boron-doped diamond powder (BDDP)-modified carbon paste electrode was developed for the determination of azithromycin (AZI), a widely used macrolide antibiotic. Experimental parameters, including modifier concentration, electrochemical technique, and operating conditions, were systematically optimized to improve analytical performance. Using square- wave voltammetry in acetate buffer solution (pH ~ 5), the proposed sensor exhibited a linear response over the concentration range of 75 ppb -449 ppm and achieved a detection limit of 74.8 ppb. The method was successfully applied to spiked river/lake water samples, providing recoveries between 86% and 107% and relative standard deviation values below 20%. These results demonstrate the sensor’s accuracy, precision, and suitability for azithromycin determination in complex environmental water matrices.
Key words: antibiotics, carbon paste electrode, boron-doped diamond powder, nanomaterials.