Desenvolvimento de novas plataformas eletroquímicas de baixo custo para o monitoramento de amoxicilina em amostras de origem farmacêutica e alimentícia

Abstract

Within the scope of this study, two low-cost electrochemical platforms were meticulously engineered for the quantification of amoxicillin in samples of whole milk, tablets, and synthetic urine. The paper electrode not only evinced reproducibility in measurements but also exhibited an expansive linear working range. A conductive ink was formulated, employing base enamel, acetone, and graphite powder, with scrupulous attention to optimizing its composition concerning the percentage of conductive material. A noteworthy discrepancy in sensor performance was discerned upon the mechanical exfoliation of its surface, resulting in an approximate 30% reduction in its charge transfer resistance. Scanning electron microscopy analyses revealed an augmentation in surface homogeneity and an enhancement in the exposure of electroactive sites post-process. A method utilizing differential pulse voltammetry was refined, yielding a linear sensor response within the range of 29.8 to 126.7 µmol L-1 . In real sample tests, under an addition and recovery assay, recovery values ranging from 90% to 103% were attained, with a detection limit of 8 µmol L-1 . Furthermore, no substantive interferences were discerned in the analytical signal in the presence of other clinically relevant pharmaceuticals. The visible laser-engraved electrode was meticulously constructed with accessibility, high scalability, and reproducibility in mind. Analyses through EIS, SEM, and RAMAN unveiled a porous surface with graphene morphologies housing abundant electroactive sites. Notably, this platform exhibited a diminished charge transfer resistance when juxtaposed with a commercial glassy carbon electrode. An electroanalytical method employing differential pulse voltammetry was devised, achieving a working range of 14.9 to 126.2 µmol L-1 and a detection limit in the order of 4.9 µmol L-1 . When applied to pharmaceutical and food samples, in an addition and recovery assay, recovery values fluctuated between 86% and 104%. In summation, both platforms epitomize promising alternatives for the analysis of the proposed samples, featuring micromolar order working ranges, coupled with precision, accuracy, and auspicious scalability.