Aqueous chloramine sensors based on molecules acting as switchable dopant sites on graphene-like carbon films

基于分子作为类石墨烯碳膜上可切换掺杂位点的水性氯胺传感器

• 批准号: 530411-2018
• 负责人: Kruse, Peter
• 金额: $ 4.37万
• 依托单位: McMaster University
• 依托单位国家: 加拿大
• 项目类别: Collaborative Research and Development Grants
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=697724
• 关键词: Aqueous; chloramine; sensors; based; molecules

Water is fundamentally important to most aspects of our existence. One of the most important monitoring parameters of drinking water quality is the level of disinfectants. If their levels are too low, microorganisms can grow in the water, which are harmful to our health. If the disinfectant levels are too high, the disinfectants themselves may be harmful, or at least unpleasant to humans. After primary disinfection at the water treatment plant is complete, disinfectant levels have to be maintained throughout the water distribution system (secondary disinfection). Chloramination is increasingly used for this purpose instead of chlorination. While its persistence is a benefit during distribution, monochloramine is harder to detect (it is odorless) and remove (it is stable) at the consumer end. For applications in health care, aqua culture, swimming pools, and in the food and beverage industry, however, complete removal of chloramines by filtration is imperative. Filter lifetime is difficult to judge just by age or water volume since it is more directly a function of filter capacity and contaminant load. Ideally, a sensor immediately after the filter could warn of breaches due to defects or exhausted capacity. Here we focus on the development of a chloramine sensor for point-of-use water filters. This work will build on a novel sensor design that our research team has recently demonstrated as effective for detecting free chlorine in drinking water. The design is based on our finding that aniline oligomers are capable of being oxidized by the free chlorine in water, thus switching on their ability to act as p-dopants for carbon nanotube films. A simple chemiresistor configuration can quantitatively detect the significant conductivity change of the nanocarbon film due to the dopant switching, and hence serve as a quantitative redox sensor across the entire relevant range. Preliminary data indicates that these sensors can also be used to detect and distinguish a variety of redox-active species. The same sensing principle can be applied to pH or other analytes by using different selectively switchable dopant molecules. Hence, we propose to develop a sensing array capable of quantitatively detecting chloramines in relevant applications for our industrial partner, 3M Canada.

水对于我们生存的大多数方面都至关重要。饮用水质量最重要的监测参数之一是消毒剂的含量。如果它们的含量太低，微生物就会在水中生长，这对我们的健康有害。如果消毒剂含量过高，消毒剂本身可能有害，或者至少对人类来说是不愉快的。水处理厂的初级消毒完成后，整个配水系统必须保持消毒剂水平（二级消毒）。为此目的，越来越多地使用氯胺化代替氯化。虽然一氯胺在分销过程中的持久性是一个好处，但一氯胺在消费者端更难检测（无味）和去除（稳定）。然而，对于医疗保健、水产养殖、游泳池以及食品和饮料行业的应用，必须通过过滤完全去除氯胺。过滤器的使用寿命很难仅通过寿命或水量来判断，因为它更直接地取决于过滤器容量和污染物负荷。理想情况下，紧接过滤器之后的传感器可以警告由于缺陷或耗尽容量而造成的破坏。在这里，我们重点开发用于使用点水过滤器的氯胺传感器。这项工作将建立在一种新颖的传感器设计的基础上，我们的研究团队最近证明该设计可有效检测饮用水中的游离氯。该设计基于我们的发现，即苯胺低聚物能够被水中的游离氯氧化，从而开启它们作为碳纳米管薄膜的 p 掺杂剂的能力。简单的化学电阻配置可以定量检测由于掺杂剂切换而导致的纳米碳膜的显着电导率变化，因此可以在整个相关范围内充当定量氧化还原传感器。初步数据表明，这些传感器还可用于检测和区分各种氧化还原活性物质。通过使用不同的选择性可切换掺杂剂分子，可以将相同的传感原理应用于 pH 值或其他分析物。 因此，我们建议为我们的工业合作伙伴 3M Canada 开发一种能够在相关应用中定量检测氯胺的传感阵列。