Nanostructured microelectrodes for electrochemical sensing in digital microfluidic devices

Darius G Rackus, Michael DM Dryden, Alex Zaragoza, Julian Lamanna, Brian Lam, Shana O Kelley, and Aaron R Wheeler University of Toronto, CANADA ABSTRACT Nanostructured microelectrodes (NMEs) are three-dimensional electrodes with superb sensitivity. Here we report the integration of NMEs with digital microfluidics (DMF), for eventual application to diagnostics outside of the laboratory. The new system was observed to outperform similar planar sensing electrodes also integrated with DMF. A rubella virus (RV) IgG immunoassay was developed to evaluate the diagnostic potential for the new system. The limit of detection of the assay (0.80 IU mL) was >10x below the World Health Organization defined cut-off for rubella immunity.