Enhancing hydroxychloroquine detection using carbon paste electrode modified with platinum nanoparticles and MWCNTs

In this study, a carbon paste electrode (CPE) modified with multi-walled carbon nanotubes (MWCNTs) and platinum nanoparticles (Pt NPs) was developed for the detection of hydroxychloroquine in environmental and biologic samples. The electrodes defined as MWCNTs/CPE and Pt NPs-MWCNTs/CPE, were subjected to characterization analyses, where their structural and morphological properties were investigated. The electrochemical measurements were carried out using cyclic and square wave voltammetry techniques. Under optimal conditions, the proposed sensor displayed a linear concentration range of 0.099–7.1 µmol L‒1 (n = 3) in 0.10 mol L−1 phosphate buffer solution at pH 6.0, with detection and quantification limits of 28 nmol L‒1 and 93 nmol L‒1, respectively. The selectivity of the proposed sensor toward hydroxychloroquine detection was verified in the presence of potential interferents, such as uric acid, glucose, urea, ascorbic acid, albumin, metals, and humic acid. For the analysis of its applicability, the sensor was successfully applied for hydroxychloroquine detection in biologic and environmental samples, where the results obtained were comparable to those obtained under spectrophotometry (reference method), thus confirming the feasibility of the method. The findings of this study show that the proposed sensor exhibits exceptional performance and is suitable for use in the detection of pharmaceuticals in different real matrices.