Using a sensitive screen-printed electrode based on printex L6 and polyaniline activated carbon for piroxicam...

This study reports the development and implementation of a straightforward, rapid, and cost-effective voltammetric technique for piroxicam (PIR) detection at nanomolar concentrations in biological and environmental samples. The method involved the use of a screen-printed electrode (SPE) enhanced with a combination of Printex L6 carbon (PL6C) and polyaniline-based activated carbon (PAC) on a chitosan film crosslinked with epichlorohydrin (CTS:EPH). The detection was carried out using square-wave adsorptive anodic stripping voltammetry (SWAdASV) in a 0.10 mol L^-1 phosphate buffer solution at pH 6.0. The approach employed yielded a low limit of detection of 4.5 × 10^-9 mol L^-1 and a linear range of 5.0 × 10^-8 to 8.8 × 10^-6 mol L^-1 (r = 0.999). The PAC-PL6C-CTS:EPH/SPE sensor was effectively employed for PIR detection in synthetic urine and river water samples, where its reliability was proven through addition and recovery tests. The results obtained from the application of the proposed voltammetric method closely matched those recorded under high-performance liquid chromatography (HPLC), which was used as a reference method. The findings show that the technique proposed in this study offers a simple, quick, and highly effective alternative mechanism for PIR detection in both biological and environmental matrices.