Implementation of a miniaturized sensor system using screen-printed carbon electrodes for on-site detection of MDMA...

3,4-Methylenedioxymethamphetamine (MDMA), commonly known as ecstasy, is a widely abused psychoactive substance, especially in the context of club and party scenes. Due to its prevalence and the associated health risks, rapid and reliable methods for its detection are essential, particularly for forensic investigations. This study presents the development of a portable sensor system for the detection of MDMA using screen-printed carbon electrodes (SPCE) and square wave voltammetry (SWV) technique. The SPEs were manually fabricated in the laboratory, and the electrochemical behavior of MDMA was thoroughly characterized, with special attention given to the influence of pH on the oxidation process. The method was optimized for quantitative analysis with a detection limit of 0.5 µM and a linear range of 2.5-50 µM. The sensor demonstrated high reproducibility, satisfactory precision (intra-day CV%: 2.1-7.1 %; inter-day CV%: 5.4-6.3 %), and excellent recovery rates (89-105 %). The system was successfully applied to the analysis of authentic ecstasy samples, and the results were consistent with those obtained by the reference UHPLC-DAD method. The fully manual fabrication, cost-effectiveness, and low detection limits of this sensor system, combined with its simplicity, portability, and reliability, suggest its strong potential as an effective and accessible tool for on-site MDMA detection in forensic applications, even in resource-limited settings.