Smartphone Nanocolorimetry for On-Demand Lead Detection and Quantitation in Drinking Water
Smartphone Nanocolorimetry for On-Demand Lead Detection and Quantitation in Drinking Water
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DOI：
10.1021/acs.analchem.8b02808
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发表时间：
2018-10-02
影响因子：
7.4
通讯作者：
Shih, Wei-Chuan
中科院分区：
文献类型：
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作者：
Hoang Nguyen;Sung, Yulung;Shih, Wei-Chuan
饮用水中的铅离子（Pb2+）污染是普通人群铅中毒的主要来源，通常通过庞大且昂贵的实验室分析仪器来检测。用于快速Pb2+感测的移动的分析装置是日益增长的需求。在此，我们报告智能手机纳米比色法（SNC）作为一种新技术来检测和量化饮用水中溶解的Pb2+。具体而言，我们采用了一个单步沉淀的方法，通过混合控制量的铬酸根离子（CrO42-）与Pb2+的溶液反应，形成高度不溶性的铬酸铅（PbCrO4）纳米粒子作为鲜艳的黄色沉淀。随后使用暗场智能手机显微镜进行纳米级的显微颜色检测和强度定量。黄色像素的强度总和与去离子水中1.37 - 175 ppb和城市自来水中5 - 175 ppb之间的Pb2+浓度具有高度可再现的关系。与传统的比色技术分析体颜色变化相比，SNC通过将纳米比色法与暗场显微镜相结合，实现了无与伦比的灵敏度，并通过将检测集成到智能手机显微镜平台中来移动金属离子检测。SNC是快速和低成本的，并有可能使个人公民在几乎任何环境设置中按需检查饮用水中的Pb2+含量。
Lead ions (Pb2+) contamination in drinking water, a major source of lead poisoning to the general population, is typically detected by bulky and costly laboratory analytical instrument. A mobile analytical device for rapid Pb2+ sensing is a growing demand. Herein, we report smartphone nanocolorimetry (SNC) as a new technique to detect and quantify dissolved Pb2+ in drinking water. Specifically, we have employed a single-step sedimentation approach by mixing a controlled quantity of chromate ion (CrO42-) to react with Pb2+ containing solutions to form highly insoluble lead chromate (PbCrO4) nanoparticles as vivid yellow precipitates. This is followed by microscopic color detection and intensity quantitation at nanoscale level using dark-field smartphone microscopy. The sum of the intensity of yellow pixels bears a highly reproducible relationship with Pb2+ concentration between 1.37 and 175 ppb in deionized water and 5-175 ppb in city tap water. In contrast to traditional colorimetric techniques analyzing bulk color changes, SNC achieves unparalleled sensitivity by combining nanocolorimetry with dark-field microscopy and mobilized the metal ions detection by integrating the detection into the smartphone microscope platform. SNC is rapid and low-cost and has the potential to enable individual citizens to examine Pb2+ content in drinking water on-demand in virtually any environmental setting.