Genetic Engineering Interdisciplinary Program, Graduate School, Kasetsart University, Chatuchak, Bangkok, Thailand.
Division of Occupational and Environmental Diseases, Department of Disease Control, Ministry of Public Health, Nonthaburi, Thailand.
J Environ Sci Health B. 2021;56(4):370-377. doi: 10.1080/03601234.2021.1888615. Epub 2021 Feb 21.
This study aimed to develop an aptasensor for paraquat detection by gold nanoparticles. The specific aptamer for paraquat was selected by using the SELEX process via capillary electrophoresis. Sixty-three aptamer candidates were amplified by asymmetric PCR and screened for paraquat binding using gold nanoparticles (AuNPs). Aggregation of AuNPs was specifically induced by desorption of paraquat binding aptamers from the surface of AuNPs as a result of aptamer-target interaction leading to the color change from red to purple. Aptamer 77F with the following sequence: 5'-AGGCTTACACCTGAAAAGCGGCTTAATTTACACTACTGTAT-3' was selected as a highly specific aptamer for paraquat. The detection limit of paraquat was 0.267 µg/mL by colorimetry and 1.573 µg/mL by the quartz crystal microbalance (QCM) technique. This aptamer showed specificity for paraquat by colorimetry. Dimethyl phophite, diethyl phophite and O,O diethyl thiophosphate potassium salt did not react by colorimetry but, exhibited a weak nonspecific reaction by QCM. This is first time that an aptasensor was used for detection of paraquat based on QCM. However, the aptasensor based on the colorimetric method simply uses a generation of a signal that can be detected by the naked eye. This technique is rapid, low cost easy to use and suitable for on-site detection of herbicide residue.
本研究旨在开发一种基于金纳米粒子的敌草快检测适体传感器。通过毛细管电泳的 SELEX 过程，选择了用于敌草快的特异性适体。通过不对称 PCR 扩增了 63 个适体候选物，并使用金纳米粒子 (AuNPs) 筛选其与敌草快的结合。由于适体-靶相互作用导致结合在 AuNPs 表面的敌草快结合适体解吸，AuNPs 发生聚集，从而导致颜色从红色变为紫色。选择具有以下序列的适体 77F 作为高度特异性的敌草快适体：5'-AGGCTTACACCTGAAAAGCGGCTTAATTTACACTACTGTAT-3'。通过比色法和石英晶体微天平 (QCM) 技术检测敌草快的检测限分别为 0.267μg/mL 和 1.573μg/mL。该适体通过比色法显示出对敌草快的特异性。二甲膦酸酯、二乙膦酸酯和 O,O-二乙基硫代磷酸钾盐在比色法中没有反应，但在 QCM 中表现出较弱的非特异性反应。这是首次使用基于 QCM 的适体传感器检测敌草快。然而，基于比色法的适体传感器简单地使用可以通过肉眼检测到的信号的产生。该技术快速、低成本、易于使用，适合现场检测除草剂残留。
