文献类型：期刊文献

英文题名：Homogeneous electrochemical detection of ochratoxin A in foodstuff using aptamer-graphene oxide nanosheets and DNase I-based target recycling reaction

作者：Sun, Ai-Li[1];Zhang, Yan-Fang[1,2];Sun, Guo-Peng[1,2];Wang, Xuan-Nian[1];Tang, Dianping[2]

通讯作者：Sun, AL[1];Wang, XN[1]

机构：[1]Xinxiang Univ, Dept Chem & Chem Engn, Inst Biotechnol, Xinxiang 453000, Peoples R China;[2]Fuzhou Univ, Key Lab Anal & Detect Food Safety MOE & Fujian Pr, Dept Chem, Fuzhou 350108, Peoples R China

第一机构：新乡学院化学化工学院

通讯机构：[1]corresponding author), Xinxiang Univ, Dept Chem & Chem Engn, Inst Biotechnol, Xinxiang 453000, Peoples R China.|[110713]新乡学院化学化工学院;[11071]新乡学院;

年份：2017

卷号：89

起止页码：659-665

外文期刊名：BIOSENSORS & BIOELECTRONICS

收录：;EI(收录号：20155201709187);Scopus(收录号：2-s2.0-84950264434);WOS:【SCI-EXPANDED(收录号:WOS:000391077000071)】；

基金：This work was financially supported by the National Natural Science Foundation of China (Grant nos.: 21405128 and 21475025) and the Research (Initial) Fund for the Doctoral Program of Xinxiang University, China (Grant no.: XRC-2012-01).

语种：英文

外文关键词：Ochratoxin A; Graphene oxide nanosheets; Homogeneous electrochemical assay; Aptasensor; DNase I-based target recycling

摘要：A simple and feasible homogeneous electrochemical sensing protocol was developed for the detection of ochratoxin A (OTA) in foodstuff on the immobilization-free aptamer-graphene oxide nanosheets coupling with DNase I-based cycling signal amplification. Thionine-labeled OTA aptamers were attached to the surface of nanosheets because of the strong noncovalent binding of graphene oxide nanosheets with nucleobases and aromatic compounds. The electronic signal was acquired via negatively charged screen printed carbon electrode (SPCE) toward free thionine molecules. Initially, the formed thionine-aptamer/graphene nanocomposites were suspended in the detection solution and far away from the electrode, thereby resulting in a weak electronic signal. Upon addition of target OTA, the analyte reacted with the aptamer and caused the dissociation of thionine-aptamer from the graphene oxide nanosheets. The newly formed thionine-aptamer/OTA could be readily cleaved by DNase I and released target OTA, which could retrigger thionine-aptamer/graphene nanocomposites with target recycling to generate numerous free thionine molecules. Free thionine molecules were captured by negatively charged SPCE, each of which could produce an electrochemical signal within the applied potentials. Under optimal conditions, graphene-based aptasensing platform could exhibit good electrochemical responses for the detection of OTA at a concentration as low as 5.6 pg/mL. The reproducibility, precision and selectivity of the system were acceptable. Importantly, the method accuracy was comparable with commercialized OTA ELISA kit when using for quantitative monitoring of contaminated wheat samples. (C) 2015 Elsevier B.V. All rights reserved.