Paper-based immunoassays

An immunoassay is a biochemical test based on the interaction between antibodies and their corresponding antigens. The traditional immunoassays, such as enzyme-linked immunosorbent assay and radioimmunoassay, are sensitive and specific in various research fields, including food safety, clinical diagnosis, and environment monitoring. However, these methods often suffer from some drawbacks, such as relying on expensive instruments and skillful technicians, and thus are hard to apply in developing countries. To address these issues, paper-based immunoassays provide an alternative solution by means of an affordable, portable, and accessible strategy in various application fields. This chapter presents the strategies of paper-based immunoassays based on different detection methods (e.g., colorimetric, thermal, electrochemical, and magnetic). Moreover, we also review the advances in paper-based immunoassays, including signal amplification strategies, automatic detections, and semiquantification or quantification. At last, we summarize the future development tendency of paper-based immunoassay in this chapter.