Aptamer-based fluorometric determination of norovirus using a paper-based microfluidic device

The authors describe a rapid and highly sensitive point-of-care device for rapid determination of noroviruses, a leading cause of acute gastroenteritis. The assay is based on the use of a norovirus-specific aptamer labeled with 6-carboxyfluorescein, and of multi-walled carbon nanotubes (MWCNT) and graphene oxide (GO). The fluorescence of the 6-FAM labeled aptamer is quenched by MWCNT or GO. In the presence of norovirus, fluorescence is recovered due to the release of the labeled aptamer from MWCNT or GO. An easy-to-make paper-based microfluidic platform was developed using a nitrocellulose membrane. The quantitation of norovirus was successfully performed. The linear range extends from 13 ng·mL⁻¹ to 13 μg·mL⁻¹ of norovirus. The detection limits are 4.4 ng·mL⁻¹ and 3.3 ng·mL⁻¹, respectively, when using MWCNT or GO. The device is simple and cost-effective, and holds the potential of rapid in-situ visual determination of noroviruses with remarkable sensitivity and specificity. Hence, it provides a new method for early identification of norovirus and a tool for early intervention when preventing the spread of an outbreak. [Figure not available: see fulltext.].