Engineers at the McKelvey School of Engineering at Washington University in St. Louis have developed a rapid, highly sensitive and accurate biosensor based on an ultrabright fluorescent nanoprobe that has the potential to be broadly deployed for COVID-19 testing. Their novel approach is described in a paper published today in Nature Biomedical Engineering.

According to senior author Srikanth Singamaneni, their plasmonic-fluor-based biosensor could be 100 times more sensitive compared with the conventional SARS-CoV-2 antibody detection methods.

Plasmonic-fluor works by increasing the fluorescence signal to background noise. It effectively turns up the brightness of fluorescent labels used in a variety of biosensing and bioimaging methods. In addition to COVID-19 testing, it could potentially be used to diagnose, for instance, that a person has had a heart attack by measuring the levels of relevant molecules in blood or urine samples.

Coronavirus Research Products
Search Now Find the right products for your coronavirus-related research. Biocompare's Coronavirus Research Products category includes commercially available antibodies, ELISA kits, proteins, strains, and PCR assays.

Using plasmonic-fluor, which is composed of gold nanoparticles coated with conventional dyes, researchers have been able to achieve up to a 6,700-fold brighter fluorescent nanolabel compared with conventional dyes, which can potentially lead to early diagnosis. Using this nanolabel as an ultrabright flashlight, they have demonstrated the detection of extremely small amounts of target biomolecules in biofluids and even molecules present on the cells.

covid

The researchers have also shown that plasmonic-fluor allows the detection of multiple proteins simultaneously. And in flow cytometry, plasmonic-fluor's brightening effect allows for a more precise and sensitive measurement of proteins on cell surface, whose signal may have been buried in the background noise using traditional fluorescent tagging.

Image: Engineers at the McKelvey School of Engineering at Washington University in St. Louis have received federal funding for a rapid COVID-19 test using a newly developed technology called plasmonic-fluor. Image courtesy of Washington University in St. Louis.