title: A Digital-Analog Microfluidic Platform for Patient-Centric Multiplexed Biomarker Diagnostics of Ultralow Volume Samples.
abstract: Microfluidic diagnostic devices have the potential to transform the practice of medicine. We engineered a multiplexed digital-analog microfluidic platform for the rapid and highly sensitive detection of 3-4 biomarkers in quadruplicate in 16 independent and isolated microfluidic unit cells requiring only a single 5 μL sample. We comprehensively characterized the platform by performing single enzyme and digital immunoassays, achieving single molecule detection and measured as low as ∼10 fM (330 fg/mL) GFP in buffer and ∼12 fM GFP in human serum. We applied our integrated digital detection mechanism to multiplexed detection of 1pM anti-Ebola IgG in human serum and were able to differentiate three common Ebola strains. To ascertain that the device can be applied in environments beyond clinical point-of-care settings, we developed a low-cost, portable hardware system to control and read out the microfluidic device and detected anti-Ebola IgG in ultralow volume whole blood samples to levels of 100 pM in a multiplexed assay format.
authors.affiliation: Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne , Lausanne 1015, Switzerland.
authors.forename: Francesco
authors.initials: F
authors.lastname: Piraino
authors.affiliation: Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne , Lausanne 1015, Switzerland.
authors.forename: Francesca
authors.initials: F
authors.lastname: Volpetti
authors.affiliation: Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne , Lausanne 1015, Switzerland.
authors.forename: Craig
authors.initials: C
authors.lastname: Watson
authors.affiliation: Institute of Bioengineering, School of Engineering, École Polytechnique Fédérale de Lausanne , Lausanne 1015, Switzerland.
authors.forename: Sebastian J
authors.initials: SJ
authors.lastname: Maerkl
keywords: ELISA; diagnostics; digital immunoassay; microarrays; microfluidics; point-of-care; single-enzyme analysis