Evolution, Uses, and Emerging Trends in Microfluidic Paper-Based Analytical Devices

Microfluidic paper-based analytical devices (µPADs) are valued of their low cost and portability, making them perfect for testing at the point of need. Their adaptability in size and shape further improves their portability, detection and analysis that can be carried out with portable devices. µPADs meet the essential demand for quick, dependable and simple testing in diverse areas, such as environmental monitoring, healthcare and food safety. This review offers a thorough overview of the development of µPADs, exploring key design factors such as the type of paper utilized and the core operational principles. Key detection methods include colorimetry, fluorescence, and electrochemistry, with recent innovations combining optical and electrochemical techniques to improve sensitivity and selectivity. In addition, distance-based detection methods are emphasized for their ability to provide instrument-free analysis and minimize error, which is especially important in resource-limited settings. The review concludes by addressing the practical challenges and requirements of µPADs, providing valuable insights for future research and advancements in the field of analytical chemistry.