Electrochemical paper-based analytical devices for environmental analysis: Current trends and perspectives

Environmental pollution is a serious problem that affects millions of people, and the demand for frequent quality monitoring is increasing. As a result, it has proven difficult to provide analytical platforms that combine high sensitivity, selectivity, and accuracy while maintaining low cost, portability, and user-friendliness. Electrochemical paper-based analytical devices (ePADs) are powerful analytical platforms that can satisfy these requirements. Paper is a superior substrate for electrochemical analysis due to its non-reactive backdrop, compatibility with both aqueous and non-aqueous analyses, and the capacity to quickly obtain a sophisticated device with high sensitivity and functionality in just a few steps. In this review, the focus is on the most recent applications of ePADs for the assessment of pollutants published in the past five years. ePADs are used for the sensitive and selective analysis of pollutants in different environmental matrices. Furthermore, the effects of nanomaterials on the fabrication of electrodes on paper-based substrates as well as on the sensitivity of electrochemical measurements, are discussed in this review. Finally, the possibility of using these ePADs in industrial and commercial applications is discussed from the authors' point of view.