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.

中文翻译：

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完全集成，简单且低成本的电化学传感器阵列，用于原位水质监测。

对于持续的水安全，尤其是在资源有限的地区，快速，准确和廉价的水质参数监控是必不可少的。大多数常规传感系统要么一次只能监视一个参数，要么缺乏用户友好的现场监视功能。完全集成的电化学传感器阵列是解决此障碍的极佳解决方案。电化学感测方法涉及水质参数的转换，其中化学相互作用转化为电信号。设计低成本，易于使用且高度灵敏的传感器阵列仍面临挑战，该传感器阵列可连续监测主要水质参数，例如pH值，游离氯，温度以及新出现的药物污染物，和重金属，而无需使用昂贵的实验室技术和训练有素的人员。在这里，我们通过实现完全集成的电化学传感系统克服了这一挑战，该系统可同时监测pH（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），弥合了信号转导，处理，无线传输和智能手机接口之间的技术鸿沟。这是通过将纳米材料和在微玻璃载玻片上制造的基于碳纳米管的传感器进行合并来实现的，这些载玻片由定制设计的读出电路，恒电位仪和Android应用程序控制。传感系统可以轻松修改和编程以集成其他传感器，可以用来监视一系列水质参数的功能。我们演示了用于监视水龙头，游泳池和湖泊水的集成系统。该系统为广泛的低成本和无处不在的环境监控应用打开了可能性。