The traumatic impact of viral infectious diseases was witnessed in the 1918 influenza pandemic, the ongoing HIV/AIDS pandemic, the most recent Ebola outbreak (Fauci A. S. et al., New Engl J Med, 2012, 366:454-461), and more. Rapid isolation, identification, and characterization of viruses from field samples are critical in the prevention of epidemics (Pennington H., Nat Rev Micro, 2004, 2:259-262). Small footprint lab-on-a-chip systems promise to rapidly analyze samples of small quantity with high sensitivity at points of care (Whitesides G. M., Nature, 2006, 422:368-373). Although many advanced virus detection methods have been reported, there has yet to be a high efficiency sample preparation system (Ritzi-Lehnert M., Expert Rev Mol Diagn, 2012, 12:189-206; Sin M. L. Y. et al., Expert Rev Mol Diagn, 2014, 14:225-244). Most previous work employed antibodies or ligands to capture known nanoscale target like viruses (Stern et al., Nature, 2007, 445:519). Existing virus sample preparation systems utilizing, e.g. immune-based capture, which requires foreknowledge of virus strain or membrane-based filtration, suffers from low efficiency and capacity due to non-uniformity of pore size and low porosity, as well as a lack of downstream virus analysis integration and lowers accessibility to the public. Label-free methods will be highly desirable for unknown viruses. In addition, it is difficult to release the captured NPs for further analysis.
There is a need for an improved method of label-free capture for small particles like viruses. The present invention meets this need.