An electrochemical aptasensor for highly sensitive detection of zearalenone based on PEI-MoS2-MWCNTs nanocomposite for signal enhancement.

In this work, an electrochemical aptasensor with a high signal response was constructed for zearalenone (ZEN) detection. Firstly, the polyethyleneimine (PEI) functionalized molybdenum disulfide (MoS2) doped multi-walled carbon nanotubes (PEI-MoS2-MWCNTs) nanohybrid was designed and prepared as sensing platform and the bioactive molecule of toluidine blue (Tb) as the signal probe. Then the synthesized platinum/gold core/shell (Pt@Au) nanoparticle was dropped on the modified electrodes to load a large amount of ZEN binding aptamer (ZBA). The variation of the electrochemical signal responses which originated from Tb was measured by cyclic voltammetry (CV) after ZEN binding to ZBA with high affinity. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and energy dispersive spectroscopy (EDS) were employed to characterize the nanomaterial. Upon the optimal conditions, the proposed aptasensor showed excellent detection performances for ZEN with a wide concentration range from 0.5 pg mL-1 to 50 ng mL-1 and the limit of detection (LOD) of 0.17 pg mL-1. Furthermore, this presented method could be feasible for determining ZEN in the real beer samples.