A screening method for the highly toxic nerve agent VX is required for forensic and clinical analysis. In this study, a simple colorimetric method using gold nanoparticles (AuNPs) was established as an efficient strategy for VX detection by the naked eye. The AuNPs changed from bright red to deep blue on addition of VX under weakly acidic conditions. In the presence of 2-(diisopropylamino)ethanethiol (DAET), which is a major hydrolysis product of VX, AuNP aggregation was observed. This aggregation occurred under weakly alkaline conditions; therefore, the associated color change occurred at a different pH to that induced by VX addition. The presence of DAET could therefore be identified by a simple pH adjustment. In addition, we developed a hand-powered extraction device for on-site primary screening. The developed method and device were applied for the detection of trace levels of VX and DAET in samples taken from simulated crime scenes.

法医和临床分析需要使用剧毒神经毒剂VX的筛选方法。在这项研究中，建立了一种使用金纳米颗粒（AuNPs）的简单比色法，作为肉眼检测VX的有效策略。在弱酸性条件下添加VX后，AuNPs从鲜红色变为深蓝色。在2-（二异丙基氨基）乙硫醇（DAET）是VX的主要水解产物的情况下，观察到AuNP聚集。这种聚集发生在弱碱性条件下。因此，相关的颜色变化发生在与添加VX诱导的pH不同的pH值下。因此，可以通过简单的pH调节来识别DAET的存在。此外，我们还开发了一种用于现场初筛的手动提取设备。