Taghdisi Seyed Mohammad, Danesh Noor Mohammad, Ramezani Mohammad, Alibolandi Mona, Nameghi Morteza Alinezhad, Gerayelou Golara, Abnous Khalil
Targeted Drug Delivery Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran; Department of Pharmaceutical Biotechnology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
Research Institute of Sciences and New Technology, Mashhad, Iran.
Talanta. 2021 Feb 1;223(Pt 1):121705. doi: 10.1016/j.talanta.2020.121705. Epub 2020 Sep 30.
Herein, an aptasensor is presented for electrochemical determination of ochratoxin A (OTA) based on nontarget-triggered production of rolling circular amplification (RCA). The surface of gold electrode is modified with thiolated complementary strand of aptamer (CS) as both capture probe and primer and OTA aptamer (Apt) as both sensing molecule and padlock probe (PLP). Following the addition of OTA, Apt/OTA conjugate is formed and detached from the electrode surface. Therefore, no RCA is produced after incubation of the modified electrode with T4 DNA ligase and phi29 DNA polymerase and a sharp current signal occurs. The analytical response ranged from 30 pM to 120 nM with detection limit of 5 pM. The designed aptasensor showed superior analytical performance in comparison with other approaches for OTA detection. Also, the approach exhibited good performance for OTA determination in spiked grape juice samples. The technique presented in this study, can be applied to develop sensors for detecting different toxins by replacing the relevant aptamers and complementary strands.
本文介绍了一种基于非靶标触发滚环扩增（RCA）的电化学检测赭曲霉毒素A（OTA）的适体传感器。金电极表面用硫醇化的适体互补链（CS）修饰，作为捕获探针和引物，并用OTA适体（Apt）作为传感分子和锁式探针（PLP）。加入OTA后，形成Apt/OTA缀合物并从电极表面脱离。因此，用T4 DNA连接酶和phi29 DNA聚合酶孵育修饰电极后不会产生RCA，而是出现尖锐的电流信号。分析响应范围为30 pM至120 nM，检测限为5 pM。与其他OTA检测方法相比，所设计的适体传感器表现出优异的分析性能。此外，该方法在加标葡萄汁样品中OTA测定方面表现良好。本研究提出的技术可通过替换相关适体和互补链，应用于开发检测不同毒素的传感器。
