Abstract Paraquat (PQ) is a kind of herbicide, which is highly toxic to human body. In this work, we proposed a fast and simple detection method for PQ in aqueous samples based on electrostatic interactions between modified gold nanoparticles (Au NPs) and PQ. Au NPs were first modified with sodium 3-mercapto-1-propanesulfonate (Au NPs-3MPS). 3MPS with negative charge can interact with nitrogen atoms of PQ with positive charge via electrostatic force. As a result, Au NPs-3MPS aggregated together. Accordingly, the color of Au NPs-3MPS colloid changed from red to blue-gray, and the UV–vis absorption spectrum changed accordingly. The detection limit of PQ is 0.1 mg/L by naked eyes, and 0.001 mg/L by UV–vis spectroscopy. Moreover, this detection method has good specific selectivity and anti-interference performance, and it has been successfully used for detecting PQ in real environmental samples and fruit juice samples.

中文翻译：

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基于功能化金纳米粒子的水样和果汁样品中百草枯的比色检测

摘要 百草枯（PQ）是一种对人体有剧毒的除草剂。在这项工作中，我们基于改性金纳米粒子 (Au NPs) 和 PQ 之间的静电相互作用，提出了一种快速简单的水样中 PQ 检测方法。Au NPs 首先用 3-mercapto-1-propanesulfonate 钠 (Au NPs-3MPS) 改性。带负电荷的 3MPS 可以通过静电力与带正电荷的 PQ 的氮原子相互作用。结果，Au NPs-3MPS 聚集在一起。相应地，Au NPs-3MPS 胶体的颜色由红色变为蓝灰色，UV-vis 吸收光谱也相应发生变化。PQ 的肉眼检测限为 0.1 mg/L，紫外-可见光谱检测限为 0.001 mg/L。而且，该检测方法具有良好的特异性选择性和抗干扰性能，