Microfluidic paper-based analytical devices for environmental analysis of soil, air, ecology and river water

Microfluidic paper-based analytical devices (mu PADs) have experienced rapid growth over the past decade due to their simple design, low cost, minimal sample requirement, and good sensitivity, selectivity and accuracy. While designed originally for point-of-care medical diagnostics, biological, and food safety applications, mu PADs are now used increasingly for environmental monitoring purposes. This review provides a detailed overview of the mu PADs developed over the past ten years for the environmental analysis of soil, air, ecology (pesticides) and river water. The review commences by introducing the fabrication techniques and detection methods used in mu PAD technology. A detailed description of the main mu PAD frameworks proposed in the past decade for environmental monitoring is then provided. The review concludes by examining the challenges facing mu PADs for environmental monitoring and identifying probable avenues of future research.