Institute of Chemical Physics, and Institute of Atomic Physics and Spectroscopy, University of Latvia, 19 Raina Boulevard, LV 1586 Riga, Latvia.
National University of Life and Environmental Sciences, 15, Geroyiv Oborony, Kyiv 03041, Ukraine.
Biosens Bioelectron. 2018 Jan 15;99:237-243. doi: 10.1016/j.bios.2017.07.056. Epub 2017 Jul 22.
Ochratoxin A (OTA) is one of the most widespread and dangerous food contaminants. Therefore, rapid, label-free and precise detection of low OTA concentrations requires novel sensing elements with advanced bio-analytical properties. In the present paper we report photoluminescence (PL) based immunosensor for the detection of OTA. During the development of immunosensor photoluminescent ZnO nanorods (ZnO-NRs) were deposited on glass substrate. Then the ZnO-NRs were silanized and covalently modified by Protein-A (Glass/ZnO-NRs/Protein-A). The latest structure was modified by antibodies against OTA (Anti-OTA) in order to form OTA-selective layer (Glass/ZnO-NRs/Protein-A/Anti-OTA). In order to improve immunosensors selectivity the surface of Glass/ZnO-NRs/Protein-A/Anti-OTA was additionally blocked by BSA. Formed Glass/ZnO-NRs/Protein-A/BSA&Anti-OTA structures were integrated within portable fiber optic detection system, what is important for the development of low cost and portable immunosensors. The immunosensor has been tested in a wide range of OTA concentrations from 10ng/ml until 20ng/ml. Interaction isotherms were derived from analytical signals of immunosensor. Association constant and Gibbs free energy for the interaction of Glass/ZnO-NRs/Protein-A/Anti-OTA with OTA were calculated, analyzed and compared with some other related results. Sensitivity range and limit of detection were determined as 0.1-1ng/ml and 10ng/ml, respectively. Interaction kinetics of ZnO-NRs with OTA was evaluated. Response time of the immunosensor toward OTA was in the range of 500-800s. Some insights related to the mechanism of PL-signal generation are proposed and discussed.
赭曲霉毒素 A（OTA）是最广泛和最危险的食品污染物之一。因此，需要具有先进生物分析特性的新型传感元件来快速、无标记和精确地检测低浓度的 OTA。在本文中，我们报告了一种基于光致发光（PL）的 OTA 检测免疫传感器。在免疫传感器的开发过程中，将发光 ZnO 纳米棒（ZnO-NRs）沉积在玻璃基底上。然后，对 ZnO-NRs 进行硅烷化处理，并通过蛋白 A（Glass/ZnO-NRs/Protein-A）进行共价修饰。最新结构通过针对 OTA 的抗体（Anti-OTA）进行修饰，以形成 OTA 选择性层（Glass/ZnO-NRs/Protein-A/Anti-OTA）。为了提高免疫传感器的选择性，将 Glass/ZnO-NRs/Protein-A/Anti-OTA 的表面用 BSA 进一步封闭。形成的 Glass/ZnO-NRs/Protein-A/BSA&Anti-OTA 结构集成在便携式光纤检测系统中，这对于开发低成本和便携式免疫传感器非常重要。该免疫传感器已在 10ng/ml 至 20ng/ml 的 OTA 浓度范围内进行了测试。从免疫传感器的分析信号中推导出相互作用等温线。计算并分析了 Glass/ZnO-NRs/Protein-A/Anti-OTA 与 OTA 相互作用的结合常数和吉布斯自由能，并与其他一些相关结果进行了比较。确定了灵敏度范围和检测限分别为 0.1-1ng/ml 和 10ng/ml。评估了 ZnO-NRs 与 OTA 的相互作用动力学。免疫传感器对 OTA 的响应时间在 500-800s 范围内。提出并讨论了与 PL 信号产生机制相关的一些见解。
