Microfluidic paper-based chips in rapid detection: Current status, challenges, and perspectives

Microfluidic paper-based chips (μPCs) are micro-laboratory analysis systems that use paper instead of traditional microfluidic substrate materials and miniaturize biochemical reactions. Based on traditional 2D μPCs, the novel μPCs are innovative 3D structure chips that are realized by fluid channel construction, channel microvalve, folding and other fluid control methods. In recent years, μPCs have developed rapidly in terms of design and integration and have been widely used in food safety, environmental residue pollution, pathogen detection and other applications. Due to their advantages of low cost, portability and satisfactory thermal stability, they have unique potential in the field of rapid detection. Herein, based on the detailed preparation, we focus on the selection of the paper substrate, microfluidic chip hydrophilic/hydrophobic processing and substrate modification. We highlight the latest research progress of μPCs in rapid detection from 2014 to 2021, and discuss the remaining challenges and future perspectives for further development.