Highly sensitive and disposable screen-printed graphene-based electrochemical sensor coupled with monolithic micro-solid-phase extraction for the determination of 3,4-methylenedioxymethamphetamine in forensic applications

Abstract

The development of a productive assay to quantify 3,4-methylenedioxymethamphetamine (MDMA) levels in human urine samples is crucial in forensic applications. In this work, we examine the use of a disposable screen-printed graphene electrode coupled with in-tip monolithic micro-solid-phase extraction (µ-SPE) for the highly selective and sensitive determination of MDMA. To satisfy this requirement, we employ a sensor based on graphene nanomaterials integrated into a compact electrochemical device to enhance the sensitivity. In-tip monolithic µ-SPE is a facile and highly effective route for extraction and preconcentration (enrichment factor ∼ 10) to improve the sensitivity. The combination of our µ-SPE and an electrochemical sensor exhibits a remarkable performance in terms of sensitivity and selectivity for MDMA analysis. A wide linear range is observed within 0.10–10.00 µg mL−1, and the lowest limit of detection is calculated to be 0.03 µg mL−1. Moreover, no interference effect from other substances is observed for MDMA detection. The feasibility of the proposed assay is evaluated, and it is successfully used in MDMA determination in human urine samples with high accuracy, precision, reproducibility, stability, and reliability. Therefore, this novel proposed method is well suited as a compact disposable device for MDMA determination in forensic applications and can be employed by relevant government organizations to correctly identify MDMA levels in narcotic addicts.