IL2 and infection: Additionally, we demonstrated the effectiveness of the scheme by performing on-device immunoassay to detect human interleukin 2 (IL-2), which is a potential biomarker for testing/diagnosis of infections, immune response, cytotoxicity, and lymphocyte transformation.33,42–44 We envision this simple microfluidic approach as a valuable tool for enabling many easy-to-perform instantaneous bioassays or rapid POC tests during emergencies or in situations where access to resources is constrained.