Graphene-based Nanosensor Device for Rapid, Onsite Detection of Dissolved Lead in Tap Water

项目摘要 公众越来越关注监测整个饮用水供应系统的水质，特别是 在使用点，最近的水灾难，如在弗林特，密歇根州，已造成严重的健康刺激 由于受污染的饮用水中的铅含量不安全，成千上万的儿童面临着各种问题。电流定量检测 含水铅的方法通常是基于实验室的，并且太昂贵和耗时，不适合于最终水 用户执行快速和现场检测。本项目旨在研究手持设备的实时， 现场检测自来水中的有毒铅。该设备集成了一种新型的微型传感器芯片， 纳米颗粒传感平台与便携式数字信号仪直接读出测试结果。该项目旨在 为了满足对自来水中总溶解铅离子的定量、实时、原位检测的需求， 一种灵敏、特异、快速、便携和具有成本效益的原型手持设备，可以在没有任何 特训 该项目的主要创新在于使用具有上级感测性能的水感测平台（即，高 灵敏度、优异的选择性和在实验室环境下和在现场设置中的快速响应）和组合 该传感器配有数字仪表，可在数十秒内直接显示检测结果。传感平台由一个 多功能混合纳米结构（即，石墨烯作为传感信号转导通道和金的载体 用化学探针功能化的纳米颗粒），其能够区分铅离子与其它水性离子 (e.g.,钙和镁）通过铅离子和特别选择的化学物质之间的特定偶联事件 探针（即，谷胱甘肽）。本项目的具体研究目标是：（1）确定 研究pH值对传感器性能的影响，以便正确解释传感结果;（2）建立模型， 通过对水中游离铅离子浓度的测量，估算出水中总溶解铅的含量，并实现了该模型 在手持设备中用于报告水中总溶解铅浓度;（3）研究潜在的干扰物种如何 在自来水中（例如，消毒副产物）影响手持设备的感测行为， 最大限度地减少不必要的干扰。手持设备的技术和商业可行性， 相关技术将确定为未来的开发和商业化。 拟议的活动将提高传感可靠性和设备完整性，最大限度地实现商业化 设备的机会。该装置的可用性有助于保障公众饮用水安全， 这种创新的传感技术可以快速，现场测试供水系统中的铅离子，特别是在 使用.该设备的框架也是可扩展的，有可能作为建立传感网络的基础， 对整个饮用水系统进行实时水质监测，提升市民饮用水安全。

PROJECT SUMMARY There is an increasing public concern about monitoring water quality in the entire drinking water supply system, especially at the point of use, spurred by recent water catastrophes, such as the one in Flint, Michigan that has caused severe health issues for thousands of children due to the unsafe level of lead in contaminated drinking water. Current quantitative detection methods for aqueous lead are often laboratory-based and are too expensive and time-consuming, unsuitable for end water users to perform fast and onsite detection. This project aims to investigate the feasibility of a handheld device for real-time, onsite detection of toxic lead in tap water. The device integrates a novel micro-sized sensor chip built upon a graphene-gold nanoparticle sensing platform with a portable digital signal meter for direct readout of testing results. This project intends to address the need for quantitative, real-time, in situ detection of total dissolved lead ions in tap water by developing a sensitive, specific, fast, portable, and cost-effective prototype handheld device that can be self-administered without any special training. Major innovations of the project lie in the use of an aqueous sensing platform with superior sensing performance (i.e., high sensitivity, excellent selectivity, and fast response under laboratory environment and in field settings) and the combination of the sensor with a digital meter for direct display of testing results in tens of seconds. The sensing platform consists of a multifunctional hybrid nanostructure (i.e., graphene as the sensing signal transduction channel and the support for gold nanoparticles functionalized with chemical probes), which is capable of differentiating lead ions from other aqueous ions (e.g., calcium and magnesium) through specific coupling events between the lead ion and the specially chosen chemical probe (i.e., glutathione) on the gold nanoparticle surface. Specific research aims of the project are to: (1) Determine the influence of pH value on the sensor performance so that sensing results can be interpreted properly; (2) Develop a model to estimate the total dissolved lead based on the measurement of free lead ion concentration in water and implement this model in the handheld device for reporting total dissolved lead concentration in water; (3) Study how potential interfering species in tap water (e.g., disinfection by-products) affect the sensing behavior of the handheld device and to identify possible strategies to minimize the undesirable interference. The technical and commercial feasibility of the handheld device and associated technology will be determined for future development and commercialization. The proposed activities will improve the sensing reliability and device integrity, maximizing the commercialization opportunities of the device. The availability of the device contributes to safeguarding the public drinking water safety, as this innovative sensing technology permits fast, onsite test of lead ions in water supply systems, particularly at the point of use. The framework of the device is also expandable with the potential to serve as the basis to build a sensing network for real-time water quality monitoring of the entire drinking water system, enhancing the public drinking water safety.