Flow-enhanced electrochemical immunosensors on centrifugal microfluidic platforms.

We present a novel fully integrated centrifugal microfluidic device with features for target antigen capture from biological samples, via a bead-based enzyme-linked immune-sorbent assay, and flow-enhanced electrochemical detection. The limit of detection (LOD) of our device for the C-reactive protein (CRP) was determined to be 4.9 pg mL(-1), a 17-fold improvement over quantification by optical density. The complete sample-to-answer protocol of our device is fully automated and takes less than 20 min. Overall, the presented microfluidic disc adds to the comparatively small number of fully integrated microfluidic-based platforms that utilize electrochemical detection and exemplifies how electrochemical detection can be enhanced by flow to successfully detect very low levels of biomarkers (e.g. pg mL(-1)).