Electrical and Computer Engineering , McMaster University , 1280 Main Street W , Hamilton , ON L8S 4K1 , Canada.
Information Science and Electronic Engineering , Zhejiang University , 38 Zheda Road , Hangzhou 310027 , P. R. China.
ACS Sens. 2020 Feb 28;5(2):412-422. doi: 10.1021/acssensors.9b02095. Epub 2020 Feb 18.
Rapid, accurate and inexpensive monitoring of water quality parameters is indispensable for continued water safety, especially in resource-limited areas. Most conventional sensing systems either can only monitor one parameter at a time or lack user-friendly on-site monitoring capabilities. A fully integrated electrochemical sensor array is an excellent solution to this barrier. Electrochemical sensing methods involve transduction of water quality parameters where chemical interactions are converted to electrical signals. The challenge remains in designing low-cost, easy-to-use, and highly sensitive sensor array that can continuously monitor major water quality parameters such as pH, free chlorine, temperature along with emerging pharmaceutical contaminants, and heavy metal without the use of expensive laboratory-based techniques and trained personnel. Here, we overcame this challenge through realizing a fully integrated electrochemical sensing system that offers simultaneous monitoring of pH (57.5 mV/pH), free chlorine (186 nA/ppm), and temperature (16.9 mV/°C) and on-demand monitoring of acetaminophen and 17β-estradiol (<10 nM) and heavy metal (<10 ppb), bridging the technological gap between signal transduction, processing, wireless transmission, and smartphone interfacing. This was achieved by merging nanomaterials and carbon nanotube-based sensors fabricated on microscopic glass slides controlled by a custom-designed readout circuit, a potentiostat, and an Android app. The sensing system can be easily modified and programmed to integrate other sensors, a capability that can be exploited to monitor a range of water quality parameters. We demonstrate the integrated system for monitoring tap, swimming pool, and lake water. This system opens the possibility for a wide range of low-cost and ubiquitous environmental monitoring applications.
快速、准确、廉价地监测水质参数对于持续的水安全至关重要，特别是在资源有限的地区。大多数传统的传感系统要么一次只能监测一个参数，要么缺乏用户友好的现场监测能力。一个完全集成的电化学传感器阵列是解决这一障碍的绝佳方案。电化学传感方法涉及水质参数的转换，其中化学相互作用被转换为电信号。挑战仍然在于设计低成本、易于使用且高度敏感的传感器阵列，该阵列可以连续监测主要水质参数，如 pH 值、游离氯、温度以及新兴的药物污染物和重金属，而无需使用昂贵的基于实验室的技术和经过培训的人员。在这里，我们通过实现一个完全集成的电化学传感系统来克服这一挑战，该系统可同时监测 pH 值（57.5 mV/pH）、游离氯（186 nA/ppm）和温度（16.9 mV/°C），并按需监测对乙酰氨基酚和 17β-雌二醇（<10 nM）和重金属（<10 ppb），弥合了信号转换、处理、无线传输和智能手机接口之间的技术差距。这是通过将纳米材料和基于碳纳米管的传感器合并到由定制设计的读出电路、恒电位仪和 Android 应用程序控制的微型玻璃载玻片上来实现的。该传感系统可以轻松修改和编程以集成其他传感器，这种能力可以用于监测各种水质参数。我们展示了用于监测自来水、游泳池和湖水的集成系统。该系统为广泛的低成本和无处不在的环境监测应用开辟了可能性。
