Herein, PtPd nanoparticles compound polyethyleneimine-functionalized reduced graphene oxide (PtPd NPs/PEI-rGO) was used as the substrate material, Exonuclease III (Exo III)-assisted triple-amplified was integrated into electrochemical platform for the detection of deoxynivalenol (DON). PtPd NPs/PEI-rGO as the substrate material increased the surface area of the electrode and improved the conductivity of the electrode. The specific binding of the DON and the aptamer triggered Exo III-assisted cyclic amplification in sample solution and generated trigger (Tr) (cycle I). The hybridization of Tr and Locking probe (LP) activated DNA Walker (W-DNA) (cycle II). Then, W-DNA run continuously with the assistance of Exo III, eventually the current signal was decreased (cycle III). However, in the absence of DON, DNA machine was not driven and the electric signal was relatively high. Under optimal conditions, the detection limit of the aptasensor is 6.9 × 10⁻⁹ mg mL⁻¹, and the detection range from 1 × 10⁻⁸ mg mL⁻¹ to 1 × 10⁻⁴ mg mL⁻¹. In addition, the stability, reproducibility, and real sample detection ability of the aptasensor were studied and obtained satisfactory results.

在此，PtPd 纳米颗粒复合聚乙烯亚胺功能化还原氧化石墨烯（PtPd NPs/PEI-rGO）作为基底材料，将核酸外切酶 III（Exo III）辅助的三重扩增集成到电化学平台中，用于检测脱氧雪腐镰刀菌烯醇（DON） . PtPd NPs/PEI-rGO 作为基底材料增加了电极的表面积并提高了电极的电导率。DON 和适体的特异性结合触发了样品溶液中的 Exo III 辅助循环扩增，并产生了触发 (Tr)（循环 I）。Tr 和锁定探针 (LP) 的杂交激活了 DNA Walker (W-DNA)（循环 II）。然后，W-DNA 在 Exo III 的帮助下连续运行，最终电流信号降低（周期 III）。然而，在没有 DON 的情况下，DNA机器没有驱动，电信号比较高。在最佳条件下，适体传感器的检测限为 6.9 × 10^-9 mg mL ^-1，检测范围为1×10 ^-8 mg mL ^-1至1 × 10 ^-4 mg mL ^-1。此外，对适体传感器的稳定性、重现性和真实样品检测能力进行了研究，取得了满意的结果。