Microfluidic Immunoassays

Immunoassays have long been widely used in a variety of applications, such as for medical diagnostics, pharmaceutical analysis, environmental, food safety testing, and for basic scientific investigations because of its simplicity, sensitivity, and specificity. Microfluidic systems, also well known as a ‘‘lab-on-a-chip’’ or a ‘‘micro-total-analysis-system’’ have attracted a lot of attention in the past two decades because of advantages associated with miniaturization, integration, and automation. A promising platform for the combination of these two technologies, microfluidic immunoassays, has been extensively explored in recent years. The aim of this article is to review recent advancements in microfluidic immunoassays. A brief introduction to immunoassays and microfluidic devices will include a literature review, followed by an in-depth discussion of essential techniques in designing a microfluidic-based immunoassay from different perspectives, including device substrates, sample/reagent transportation, surface modification, immobilization, and detection schemes. Finally, future perspectives on microfluidic immunoassays will be provided. These developments with microfluidic immunoassays may provide a promising tool for automatic, sensitive, and selective measurements in practical applications. ( JALA 2010;15:253–74)