A digital microfluidic device with integrated nanostructured microelectrodes for electrochemical immunoassays

作者：Rackus Darius G; Dryden Michael D M; Lamanna Julian; Zaragoza Alexandre; Lam Brian; Kelley Shana O; Wheeler Aaron R

来源：Lab on a Chip, 2015, 15(18): 3776-3784.

DOI：10.1039/c5lc00660k

Nanostructured microelectrodes (NMEs) are three-dimensional electrodes that have superb sensitivity for electroanalysis. Here we report the integration of NMEs with the versatile fluid-handling system digital microfluidics (DMF), for eventual application to distributed diagnostics outside of the laboratory. In the new methods reported here, indium tin oxide DMF top plates were modified to include Au NMEs as well as counter and pseudoreference electrodes. The new system was observed to outperform planar sensing electrodes of the type that are typically integrated with DMF. A rubella virus (RV) IgG immunoassay was developed to evaluate the diagnostic potential for the new system, relying on magnetic microparticles coated with RV particles and analysis by differential pulse voltammetry. The limit of detection of the assay (0.07 IU mL(-1)) was >100x below the World Health Organization defined cut-off for rubella immunity. The sensitivity of the integrated device and its small size suggest future utility for distributed diagnostics.

• 出版日期2015