By Kathleen Berger, Executive Producer for Science & Technology
Before the pandemic, Srikanth Singamaneni was working towards a solution for medical testing. Singamaneni and his team had already created a technology platform for the detection of proteins present with diseases. It’s a rapid, highly sensitive and accurate biosensor proven to detect lower quantities of proteins related to certain diseases. With COVID-19, the National Science Foundation awarded his lab over $100,000 to advance the technology for SARS-Co-V-2.
“Because this biolabeling strategy is completely new that we have come up with, we are hoping that COVID-19 is going to be the first disease for which we will be using this technology,” said Srikanth Singamaneni, PhD, a professor of mechanical engineering and materials science at the McKelvey School of Engineering at Washington University in St. Louis.
His lab’s biosensor is based on an ultrabright fluorescent nanoprobe, called plasmonic-fluor. Plasmonic-fluor effectively turns up the brightness of fluorescent labels used in a variety of biosensing and bioimaging methods.
Plasmonic-fluor is composed of gold or silver nanoparticles that serve as beacons. Brighter beacons mean fewer captured proteins are needed to determine their presence.
“All we are doing is replacing the current label with this brighter label so that you can detect it at much lower concentrations and much quicker,” explained Singamaneni.
He said detection takes minutes rather than hours. Singamaneni’s team is developing a rapid SARS-Co-V-2 antibody test, as well as a rapid antigen test for active COVID-19 infections.
Compared to conventional detection methods, this biosensor has nearly a 400-fold enhancement in sensitivity detecting antibodies against a key structural protein of SARS-Co-V-2, and a 70-fold enhancement against the receptor-binding domain of the coronavirus strain. And the team has been working towards improving sensitivity even more.
“We’re using recombinant viral proteins made in the lab as bait to capture antibodies that would be present in patient’s serum,” said Jeremiah Morrissey, PhD, collaborating research professor with Washington University School of Medicine in St. Louis.
Morrissey’s role is to greatly optimize conditions to detect antibodies for COVID-19. The biosensor’s ability for increased sensitivity would allow clinicians and researchers to more easily find positive cases and lessen the chance of false negatives. They are proving this highly sensitive technique has the potential to be more specific, accurate and much faster than current testing.
The discoveries for antibody testing could then be used for rapid detection of COVID-19 infections.
“Using antibodies that actually detect these viral proteins, it could be possible to reverse the situation and use them to detect active virus,” explained Morrissey.
“In this particular case, antigen testing is going to be very powerful,” said Singamaneni. “Unfortunately, antigen testing traditionally has been a problem because most of the antigen tests are not as sensitive, but we are hoping to solve that problem. That is, to improve the sensitivity of this antigen test.”