In this paper, an ultrasensitive nanochannel sensor has been proposed for label-free Ochratoxin A (OTA) assay in combination with graphene oxide (GO) and catalyzed hairpin assembly (CHA). The high-performance sensor is segmented into two parts. One is composed of graphene oxide (GO) and DNA probes. In the presence of target OTA, OTA works as a catalyst to trigger the self-assembly pathway of the two probes and initiate the cycling of CHA circuits, which results in numerous double-stranded DNAs (dsDNA) in solution. The excess ssDNA probes are removed by GO. The other part is composed of biomimetic nanochannel coated with polyethyleneimine (PEI) and Zr⁴⁺, which can quantify the concentration of OTA by detecting the dsDNA in solution. The nanofluidic device has a detection limit of as low as 6.2 pM with an excellent selectivity. The nanochannel based assay was used to analyse food samples (red wine) with satisfied results. Thus, the proposed analytical method will provide a new approach the detection of OTA and can be applied for quality control to ensure food safety.

本文提出了一种超灵敏的纳米通道传感器，用于结合氧化石墨烯（GO）和催化发夹组件（CHA）的无标记O曲霉毒素A（OTA）测定。高性能传感器分为两部分。一种由氧化石墨烯（GO）和DNA探针组成。在存在目标OTA的情况下，OTA充当催化剂来触发两个探针的自组装途径并启动CHA循环，从而在溶液中产生大量双链DNA（dsDNA）。GO去除了多余的ssDNA探针。另一部分由涂有聚乙烯亚胺（PEI）和Zr ⁴⁺的仿生纳米通道组成，可通过检测溶液中的dsDNA来量化OTA的浓度。纳米流体装置的检测极限低至6.2 pM，具有出色的选择性。基于纳米通道的分析用于分析食品样品（红酒），结果令人满意。因此，所提出的分析方法将提供一种检测OTA的新方法，并可用于质量控制以确保食品安全。