Affiliation:
1. Hanan International Joint Laboratory of Food Green Processing and Quality Safety Control, National Demonstration Center for Experimental Food Processing and Safety Education, College of Food and Bioengineering, Henan University of Science and Technology, Luoyang 471000, China
2. School of Food Science and Technology, Jiangnan University, Wuxi 214122, China
Abstract
Sensitive detection of ochratoxin A (OTA) is significant and essential because OTA may pose risks to human and animal health. Here, we developed an electrochemical aptasensor for OTA analysis using polyamidoamine (PAMAM) dendrimers as a signal amplifier. As a carrier, PAMAM has numerous primary amino groups that can be coupled with thiolated complementary strand DNA (cDNA), allowing it to recognize aptamers bound to the surface of horseradish peroxidase (HRP)-modified gold nanoparticles (AuNPs), thereby improving the sensitivity of the aptasensor. When monitoring the positive samples, OTA was captured by the aptamer fixed on the HRP-conjugated AuNP surface by specific recognition, after which the formed OTA-aptamer conjugates were detached from the electrode surface, ultimately decreasing the electrochemical signal monitored by differential pulse voltammetry. The novel aptasensor achieved a broad linear detection range from 5 to 105 ng L−1 with a low detection limit of 0.31 ng L−1. The proposed aptasensor was successfully applied for OTA analysis in red wine, with recovery rates ranging from 94.15 to 106%. Furthermore, the aptasensor also exhibited good specificity and storage stability. Therefore, the devised aptasensor represents a sensitive, practical and reliable tool for monitoring OTA in agricultural products, which can also be adapted to other mycotoxins.
Funder
National Natural Science Foundation of China the National Key Research and Development Program
National Natural Science Foundation of China
Postgraduate Education Reform and Quality Improvement Project of Henan Province
Natural Science Foundation of Henan
Subject
Clinical Biochemistry,General Medicine,Analytical Chemistry,Biotechnology,Instrumentation,Biomedical Engineering,Engineering (miscellaneous)