LoRaStat: A Low-Cost Portable LoRaWAN Potentiostat for Wireless and Real-Time Monitoring of Water Quality and Pollution

This article presents a low-power, portable potentiostat integrating the wireless communication of the long-range wide-area network (LoRaWAN). This device provides a cost-effective solution for conducting electrochemical measurements of ammonium (NH $_{{4}}^{+}$ ), nitrate (NO $_{{3}}^{-}$ ), and calcium (Ca $^{{2}{+}}$ ) levels in aqueous environment. In addition, the system is equipped with supplemental sensors to monitor the temperature and moisture of the medium, facilitating more comprehensive sensing and compensation. Furthermore, this potentiostat enables multiple electrochemical techniques, such as cyclic voltammetry (CV) and zero current potentiometry (ZCP), to analyze different analytes’ redox behavior. The system can perform in-sensor local data analysis to improve sensing efficiency. By optimizing power consumption, the system can perform continuous sensing for over a month, making it suitable for long-term monitoring. The ability to precisely and quickly measure a wide current range spanning from 15 nA to 15 mA facilitates tracking of analyte concentration variations, thereby enabling the detection of even minor changes. A comprehensive comparison between our system and a commercial Metrohm potentiostat under various conditions validates the reliability and performance of LoRaStat.