Low-cost and portable 3D-printed sensor for the determination of secnidazole in pharmaceutical and seized drug samples

Abstract

Additive manufacturing (3D printing), particularly fused deposition modeling (FDM), has rapidly advanced, offering customized designs, reduced waste, lower costs, and fast prototyping for electroanalytical applications. Herein, the electrochemical secnidazole (SCZ) behavior was studied using additive manufactured electrodes (AMEs) based on commercial carbon black and polylactic acid (PLA) conductive filament. Before use, AMEs were submitted to electrochemical/chemical activation (+1.4 V and −1.0 V, both for 200 s) in basic medium (0.5 mol L⁻¹ NaOH). Under optimized square wave voltammetry (SWV) conditions and using 0.12 mol L⁻¹ Britton Robinson buffer (pH = 2.0) as supporting electrolyte, SCZ exhibited excellent linearity within the concentration range of 2.5 to 250.0 μmol L⁻¹ (R² = 0.998). The proposed method was successfully applied to detect and quantify SCZ in pharmaceutical and seized samples. The obtained results were statistically similar (95% confidence level) to the values obtained by HPLC. These findings demonstrate that the 3D-printed electrodes developed in this study provide a cost-effective, facile, and highly sensitive platform for on-site SCZ analysis, presenting significant potential for future forensic applications.