Direct capture and smartphone quantification of airborne SARS-CoV-2 on a paper microfluidic chip

Sangsik Kim, Patarajarin Akarapipad, Brandon T. Nguyen, Lane E. Breshears, Katelyn Sosnowski, Jacob Baker, Jennifer L. Uhrlaub, Janko Nikolich-Žugich, Jeong-Yeol Yoon

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


SARS, a new type of respiratory disease caused by SARS-CoV, was identified in 2003 with significant levels of morbidity and mortality. The recent pandemic of COVID-19, caused by SARS-CoV-2, has generated even greater extents of morbidity and mortality across the entire world. Both SARS-CoV and SARS-CoV-2 spreads through the air in the form of droplets and potentially smaller droplets (aerosols) via exhaling, coughing, and sneezing. Direct detection from such airborne droplets would be ideal for protecting general public from potential exposure before they infect individuals. However, the number of viruses in such droplets and aerosols is too low to be detected directly. A separate air sampler and enough collection time (several hours) are necessary to capture a sufficient number of viruses. In this work, we have demonstrated the direct capture of the airborne droplets on the paper microfluidic chip without the need for any other equipment. 10% human saliva samples were spiked with the known concentration of SARS-CoV-2 and sprayed to generate liquid droplets and aerosols into the air. Antibody-conjugated submicron particle suspension is then added to the paper channel, and a smartphone-based fluorescence microscope isolated and counted the immunoagglutinated particles on the paper chip. The total capture-to-assay time was <30 min, compared to several hours with the other methods. In this manner, SARS-CoV-2 could be detected directly from the air in a handheld and low-cost manner, contributing to slowing the spread of SARS-CoV-2. We can presumably adapt this technology to a wide range of other respiratory viruses.

Original languageEnglish (US)
Article number113912
JournalBiosensors and Bioelectronics
StatePublished - Mar 15 2022


  • Airborne pathogens
  • Bioaerosol
  • COVID-19
  • Paper microfluidics
  • Respiratory virus
  • Smartphone microscope

ASJC Scopus subject areas

  • Biotechnology
  • Biophysics
  • Biomedical Engineering
  • Electrochemistry


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