Autonomous capillary microfluidic immunoassay with integrated detection using microfabricated photodiodes: Towards a point-of-care device

Microfluidic technologies have demonstrated great potential for the development of point-of-care (PoC) sensing applications. Several advantages have been extensively reported, such as reductions of the volume of required reagents and of the time of analysis, and the ability to perform multiplexed analysis at reduced costs and high speeds. In this paper an innovative fluid handling strategy with direct impact on the development of PoC devices is demonstrated using capillary microfluidics integrated with microfabricated photodiodes as a lab-on-chip biosensing platform. The different solutions required to perform an immunoassay are allowed to flow sequentially, autonomously, and without mixing. Integrated detection and quantification of an antibody-antigen molecular recognition reaction was demonstrated on-chip using microfabricated amorphous silicon photodiodes.