Inline analysis techniques, where detection can be performed directly in the droplets on a digital microfluidic device, are desirable because they minimize the complexity of an experiment and can allow real-time monitoring of chemical changes. Several inline techniques have been coupled with DMF, but electrochemical analysis presents several advantages, including label-free detection of a wide variety of analytes and compact and inexpensive instrumentation. Electroanalysis is particularly well-suited for integration with DMF, given the (inherent) reliance of the latter on patterned, discretely addressable electrodes (the open-source DStat is a convenient, open-source tool that can be used to link electroanalysis with DMF). We are currently exploring electrochemical detection methods for many applications including quantitative analysis and immunoassays. For more, see our recent review paper describing the convergence of microfluidics and electrochemistry.
Yu, Y.; Shamsi, M.H.; Krastev, D.L.; Dryden, M.D.M.; Leung, Y.; Wheeler, A.R. "A Microfluidic Method for Dopamine Uptake Measurements in Dopaminergic Neurons" Lab on a Chip, 2016, 16, 543-552. Supporting info.
Shamsi, M.H.; Choi, K.; Ng, A.H.C.; Chamberlain, M.D.; Wheeler, A.R. "Electrochemiluminescence on Digital Microfluidics for MicroRNA Analysis" Biosensors and Bioelectronics, 2015, 77, 845-852. Supporting info.
Dryden, M.D.M.; Wheeler, A.R. "DStat: A Versatile, Open-Source Potentiostat for Electroanalysis and Integration" PLoS ONE, 2015, 10, e0140349. Supporting info. Movie.
Rackus, D.G.; Dryden, M.D.M.; Lamanna, J.; Zaragoza, A.; Lam, B.; Kelley, S.O.; Wheeler, A.R. "A Digital Microfluidic Device with Integrated Nanostructured Microelectrodes for Electrochemical Immunoassays" Lab on a Chip, 2015, 15, 3776-3784. Supporting info.
Shamsi, M.H.; Choi, K.; Ng, A.H.C.; Wheeler, A.R. "A digital microfluidic electrochemical immunoassay" Lab on a Chip 2014, 14, 547-554.
Dryden, M.D.M.; Rackus, D.G.; Shamsi, M.H.; Wheeler, A.R. "Integrated Digital Microfluidic Platform for Voltammetric Analysis" Analytical Chemistry 2013, 85, 8809-8816.