A droplet-based fluorescence polarization immunoassay (dFPIA) platform for rapid and quantitative analysis of biomarkers

Herein, we describe for the first time the integration of pneumatic micro-pumps with droplet-based microfluidic systems as basic platform for the rapid detection and quantitation of biomarkers. Specifically, we combine this microfluidic platform with fluorescence polarization detection to identify and quantify the potent blood vessel inducing protein bovine angiogenin within cow's milk in high-throughput. The droplet-based fluorescence polarization immunoassay is successful in accurately determining the concentration (4.84±1.21 μg/mL) of bovine angiogenin in cow's milk, affords a 10 fold reduction in dead volumes when compared to conventional droplet-based microfluidic experiments and requires an total sample volume of less than 1 nL.