A highly efficient DNA biosensor based on 2D-europium/MoS₂ nanocomposites for rifampicin detection

In this study, a sensitive rifampicin (RF) detection platform was established using a highly efficient electrochemical DNA biosensor. The sensing platform was constructed through the modification of a carbon paste electrode (CPE) with two-dimensional europium(III)–molybdenum disulfide nanocompsites (2D-Eu(III)/MoS₂) and immobilized double-stranded DNA. This work was designed to leverage the synergistic properties of MoS₂ nanocompsites and europium(III) to achieve enhanced electrochemical performance for drug–DNA interaction analysis. The nanomaterial was characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), and energy-dispersive X-ray (EDX) techniques. Differential pulse voltammetry (DPV) was employed to monitor the guanine response, which decreased significantly due to the preferential binding of RF to DNA. The biosensor exhibited excellent sensitivity of 0.103 μA/μM, a limit of detection (LOD) of 38.0 nM, and a linear detection range of 0.09–65.0 μM. Successful application was demonstrated in real samples, including pharmaceutical formulations, serum, and urine. In real sample analysis, the biosensor showed recoveries of 96–104 % with relative standard deviation (RSD) below 4.0 %, demonstrating high accuracy and reliability for practical applications. The innovative aspect of this study was in the design of a 2D-Eu(III)/MoS₂-based nanoplatform that enhances DNA loading capacity and amplifies electrochemical activity, providing a superior sensing system for RF compared to previously reported sensors.