Sensitive, Low-Cost Detection of SARS-CoV-2 from Clinical Saline Gargle Samples Using Smartphone Fluorescence Microscope

This invention is a method of rapidly detecting SARS-CoV-2 in clinical saline samples using a smartphone fluorescence microscope-based immunofluorescence. This method can detect samples of SARS-CoV-2 in saline gargle solutions down to 10 ag/μl. A saline sample is collected, loaded onto a paper-based microfluidic chip, and analyzed using a smartphone-based fluorescence microscope. The method uses lower-cost materials to detect virus samples in a saline solution and is more sensitive that similar rapid kits. The method also has high sensitivity, specificity, and accuracy, hitting 100%, 88%, and 93% respectively.

The COVID-19 pandemic has exposed society’s need for rapid, low cost, highly sensitive diagnostic tests. Many tests have been developed throughout the pandemic but many of them require expensive laboratory equipment and may have long processing times, especially in high case volume periods. Additionally, many of the point-of-care tests are inexpensive and user friendly, but they often have inferior sensitivity. Many of these existing methods also require uncomfortable nasal swabs, which may expose healthcare staff to the virus. 

This testing method resolves these problems by using a saline gargle solution and a smartphone fluorescence microscope. The saline gargle samples are easy to collect and are easily obtained from patients and pose less risk to healthcare staff during sample collection. The smartphone fluorescence microscope is also more readily available than most lab testing equipment. This method is not only simple and much more cost effective than other rapid testing methods but is also highly accurate. In testing, the sensitivity, specificity, and accuracy, was 100%, 88%, and 93% respectively.Additionally, this method can also be used to detect other respiratory viruses. 

  • Rapid COVID-19 Detection


  • Simple to use
  • Inexpensive
  • Rapid
  • Highly Accurate
  • Applicable to detect other respiratory viruses


Contact Information

TTO Home Page:

Name: Tod McCauley

Title: Assistant Director of Licensing, CALS

Department: TLA


Phone: 520-621-9493