Zhu Chengxi, Liu Xiaohong, Li Yuye, Yu Dongmei, Gao Qian, Chen Lixing
School of Electrical and Information Engineering, Jiangsu University of Technology, Changzhou 213001, China.
Key Laboratory of Modern Agricultural Equipment and Technology, Ministry of Education, School of Agricultural Engineering, Jiangsu University, Zhenjiang 212013, China.
Talanta. 2023 Feb 1;253:123966. doi: 10.1016/j.talanta.2022.123966. Epub 2022 Sep 27.
Organophosphorus pesticides (OPs) are one of the most frequently used pesticides in agriculture, and their residues in environment have caused serious human health and environmental concerns. In this work, we reported a dual-ratiometric electrochemical aptasensor based on carbon nanohorns/anthraquinone-2-carboxylic acid/Au nanoparticles (CNHs/AQ/AuNPs) for simultaneous detection of malathion (MAL) and omethoate (OMT). Here, CNHs/AQ/AuNPs composites were synthesized by a simple room temperature method, and used as a substrate to generate a reference signal (I) and enlarge response signals. Hairpin DNA was then immobilized, offering independent and specific binding sites to further adsorb MB-labelled MAL aptamer (MB-Apt1) and Fc-labelled OMT aptamer (Fc-Apt2). Upon the addition of MAL or OMT, the formation of aptamer-target complex caused the release of MB-Apt1 or Fc-Apt2 from the electrode, resulting in a decrease in I or I, while I kept unchanged. Based on this principle, the ratiometric signals of I/I and I/I were used to simultaneously detect MAL and OMT, offering a linear range of 3 pg mL to 3 ng mL for MAL and 10 pg mL to 10 ng mL for OMT, and no significant cross-reactivity existed. By taking advantage of the excellent conductivity and large specific area of CNHs/AQ/AuNPs and the stable two-dimensional structure of hairpin DNA, the aptasensor exhibited high sensitivity, selectivity and reliability. Our work has offered a novel way for simultaneous detection of multiple OPs.
有机磷农药（OPs）是农业中使用最频繁的农药之一，其在环境中的残留已引起严重的人类健康和环境问题。在这项工作中，我们报道了一种基于碳纳米角/蒽醌-2-羧酸/金纳米粒子（CNHs/AQ/AuNPs）的双比率电化学适体传感器，用于同时检测马拉硫磷（MAL）和氧乐果（OMT）。在此，通过简单的室温方法合成了CNHs/AQ/AuNPs复合材料，并将其用作底物以产生参考信号（I）并放大响应信号。然后固定发夹DNA，提供独立且特异的结合位点，以进一步吸附甲基蓝标记的MAL适体（MB-Apt1）和二茂铁标记的OMT适体（Fc-Apt2）。加入MAL或OMT后，适体-靶标复合物的形成导致MB-Apt1或Fc-Apt2从电极上释放，导致I或I降低，而I保持不变。基于此原理，I/I和I/I的比率信号用于同时检测MAL和OMT，MAL的线性范围为3 pg mL至3 ng mL，OMT的线性范围为10 pg mL至10 ng mL，且不存在明显的交叉反应。利用CNHs/AQ/AuNPs优异的导电性和大比表面积以及发夹DNA稳定的二维结构，该适体传感器表现出高灵敏度、选择性和可靠性。我们的工作为同时检测多种有机磷农药提供了一种新方法。
