Disposable paper-based electrochemical metal ion sensors for water safety testing

描述(申请人提供)：这一阶段的申请旨在开发一种可推广的电化学生物传感平台，用于检测水中的金属离子。具体地说，该项目的主要目标是验证一个方便、经济高效的电化学离子(E-ion)传感平台的设计，用于直接检测饮用水中的汞(Hg2+)、银(Ag+)和铜(Cu2+)等金属离子污染物。虽然以前开发的金属离子传感器具有优异的灵敏度和选择性，但到目前为止还没有实现适用于广泛金属离子检测的通用传感器体系结构。E-ion传感器的信号机制依赖于DNA识别探针在目标结合时的动力学抑制，这涉及到链间金属络合，从而创建了一种在使用交流伏安法进行询问时固有的“信号关闭”的传感器。然而，通过改变方波伏安法中的应用频率，这些传感器可以转换为信号导通传感器，这通常是更可取的。更重要的是，这些传感器将在镀金丝网印刷碳电极阵列上制造，使它们能够以相对较低的成本大规模生产。这些传感器的灵敏度和选择性应该与当前的光学方法相媲美，同时提供直接电化学检测的改进的稳定性、可重用性和操作便利性。我们的最终目标是开发一种廉价的生物传感器阵列来监测饮用水中金属离子污染物的水平。该传感器阵列的“现实世界”适用性将通过展示对实际家庭水样中Hg2+、Ag+和Cu2+的灵敏和选择性检测来验证。拟议项目的成功完成将为用户提供一种经济和简单的方法，以确保饮用水和其他家庭应用的水质。拟议的研究可能会对人类健康和生活质量产生重大积极影响，特别是对那些居住在资源相对较少的农村和偏远地区的人。

DESCRIPTION (provided by applicant): This Phase I application aims at developing a generalizable electrochemical biosensing platform for detection of metal ions in water. Specifically, the main objective of the project is to validate the design of a convenient, cost-effective electrochemical ion (E-ION) sensing platform for direct detection of metal ion contaminants such as mercury (Hg2+), silver (Ag+), and copper (Cu2+) in drinking water. While previously developed metal ions sensors have been demonstrated to possess exceptional sensitivity and selectivity, no generalizable sensor architecture that is applicable to the detectin of a wide range of metal ions has been realized to date. The E- ION sensor's signaling mechanism relies on the dampening of the DNA recognition probe dynamics upon target binding which involves inter-strand metal complexation, thereby creating a sensor that is inherently "signal-off" when interrogated using alternating current voltammetry. However, by varying the applied frequency in square wave voltammetry, these sensors can be converted into "signal-on" sensors, which is, in general, more desirable. More importantly, these sensors will be fabricated on a gold-plated screen-printed carbon electrode array, enabling them to be mass-produced at relatively low cost. The sensitivity and selectivity of these sensors should be comparable to current optical approaches, while offering the improved stability, reusability and operational convenience of direct electrochemical detection. Our ultimate goal is to develop an inexpensive biosensor array to monitor levels of metal ion contaminants in drinking water. The "real-world" applicability of the sensor array will be validated by demonstrating sensitive and selective detection of Hg2+, Ag+, and Cu2+ in real household water samples. Successful completion of the proposed project will provide consumers with an economical and simple method to ensure water quality for both drinking and other household applications. The proposed research could have a major positive impact on human health and quality of life, especially for those who reside in relatively low resources, rural and remote areas.