This study reports an insightful portable vector network analyser (VNA)-based measurement technique for quick and selective detection of Hg ²⁺ ions in nanomolar (nM) range using homocysteine (HCys)-functionalised quartz-crystal-microbalance (QCM) with cross-linked-pyridinedicarboxylic acid (PDCA). The excessive exposure to mercury can cause damage to many human organs, such as the brain, lungs, stomach, and kidneys, etc. Hence, the authors have proposed a portable experimental platform capable of achieving the detection in 20–30 min with a limit of detection (LOD) 0.1 ppb (0.498 nM) and a better dynamic range (0.498 nM–6.74 mM), which perfectly describes its excellent performance over other reported techniques. The detection time for various laboratory-based techniques is generally 12–24 h. The proposed method used the benefits of thin-film, nanoparticles (NPs), and QCM-based technology to overcome the limitation of NPs-based technique and have LOD of 0.1 ppb (0.1 μg/l) for selective Hg ²⁺ ions detection which is many times less than the World Health Organization limit of 6 μg/l. The main advantage of the proposed QCM-based platform is its portability, excellent repeatability, millilitre sample volume requirement, and easy process flow, which makes it suitable as an early warning system for selective detection of mercury ions without any costly measuring instruments.

中文翻译：

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使用具有交联吡啶二甲酸的同型半胱氨酸功能化石英晶体微天平检测 Hg2+ 离子的高选择性传感器


本研究报告了一种基于便携式矢量网络分析仪 (VNA) 的富有洞察力的测量技术，可使用具有交叉功能的同型半胱氨酸 (HCys) 功能化石英晶体微天平 (QCM) 快速选择性地检测纳摩尔 (nM) 范围内的 Hg ²⁺离子连接吡啶二甲酸（PDCA）。过量接触汞会对人体多个器官造成损害，如大脑、肺、胃、肾脏等。因此，作者提出了一种便携式实验平台，能够在有限的时间内实现20-30分钟的检测。检测精度 (LOD) 0.1 ppb (0.498 nM) 和更好的动态范围 (0.498 nM–6.74 mM)，完美地描述了其优于其他报道技术的卓越性能。各种实验室技术的检测时间一般为 12-24 小时。所提出的方法利用了薄膜、纳米颗粒 (NP) 和基于 QCM 的技术的优点，克服了基于 NP 的技术的局限性，并具有 0.1 ppb (0.1 μg/l) 的 LOD，用于选择性 Hg ²⁺离子检测。比世界卫生组织规定的 6 微克/升的限值低很多倍。所提出的基于 QCM 的平台的主要优点是其便携性、出色的重复性、毫升样品量要求和简单的工艺流程，这使得它适合作为选择性检测汞离子的预警系统，而无需任何昂贵的测量仪器。