Nb.Bbvci-Triggered Bipedal DNA Walking Strategy for Ultrasensitive Detection of Zearalenone

Abstract

In this work, an electrochemical aptamer sensing platform combining magnetic separation technology and Nb.BbvCI-triggered bipedal DNA walking strategy was constructed for ultrasensitive assay of ZEN based on Ce3NbO7/CeO2@Au hollow nanospheres as electrode modification material and PdNi@MnO2/MB as signal label. Importantly, the Ce3NbO7/CeO2 hollow nanospheres synthesized by hydrothermal method were combined with Au nanoparticles and applied to the electrode surface. The as-prepared Ce3NbO7/CeO2@Au possessed a large surface area, excellent electrical conductivity, stability, low toxicity and provided more binding sites. PdNi@MnO2 with high specific surface area and porosity combining with MB was introduced into electrodes as signal label. The proposed aptasensor utilized the advantages of specific recognition of aptamers and target molecules to release DNA walker, and then the bipedal DNA walker were triggered recycle by Nb.BbvCI to release more signal probes. The feasibility of this strategy was recorded by the differential pulse voltammetry (DPV) method. Under the optimized conditions, the electrochemical aptasensor exhibited a wide linear dynamic range from 1×10-4  to 1×103 ng mL-1 with a low detection limit of 4.57 × 10–6 ng mL-1. Moreover, the aptasensor had high selectivity, good stability, excellent repeatability and provided an effective method for the trace detection of ZEN in real samples.

Keywords: Zearalenone, Ce3NbO7/CeO2@Au, PdNi@MnO2, Electrochemical aptasensor, Bipedal DNA walker