At Posner Research Group, we investigate integration of electrokinetic techniques into paper-based paper microfluidic devices with the goal to improve their limit of detection and sensitivity for clinical and diagnostic applications. Paper substrates have been widely used to construct point-of-care lateral flow immunoassay diagnostic devices like the home pregnancy test. Paper-based microfluidic devices are robust and relatively simple to operate, compared to channel microfluidic devices, which is perhaps their greatest advantage and the reason they have reached a high level of commercial success. However, paper devices may not be well suited for integrated sample preparation, such as sample extraction and preconcentration, which is required in complex samples with low analyte concentrations. We developed a rapid POC NAAT with integrated sample preparation and amplification using electrokinetics and paper substrates. We use simultaneous isotachophoresis (ITP) and recombinase polymerase amplification (RPA) to rapidly extract, amplify, and detect target nucleic acids from serum and whole blood in a paper-based format. Our test is rapid (results in less than 20 min) and made from low-cost materials, indicating its potential for detecting infectious diseases and monitoring viral infections at the POC in low resource settings.
1. A.T. Bender, M.D. Borysiak, A.M. Levenson, L. Lillis, D.S. Boyle, J.D. Posner. 2018. “Semi-quantitative nucleic acid test with simultaneous isotachophoretic extraction and amplification.” Analytical Chemistry 90 (12), pp 7221–7229. doi | pdf