A team of engineers and infectious disease researchers at Washington University in St. Louis developed a new rapid point-of-care diagnostic test that is 1,000 times more sensitive than conventional tests.
One of the lead researchers, Srikanth Singamaneni, PhD, said in a Feb. 8 school press statement that the test is capable of picking up "even very small concentrations of antibodies and antigens, typical markers of infection, and give clinicians clear, quick results without the need for specialized equipment."
Right now, the new kind of tests only detect COVID-19 antigens, but their goal is to expand the range of viruses that can be found using the ultrasensitive tests.
Lateral-flow assays are a form of inexpensive, rapid diagnostic testing that have been in use since 1959, but are known to be much less accurate than laboratory testing. By incorporating plasmonically active antibody-conjugated fluorescent nanoparticles, researchers were able to not only make these tests more sensitive and accurate, but also display the results in a bright color on the strip in only 20 minutes.
"It's like turning up the volume on standard color-changing test strips," Jeremiah Morrissey, PhD, a co-author of the research and a research professor at Washington University's School of Medicine, said in a school press statement. "Instead of getting a faint line indicating only a positive or negative result, the new p-LFAs give clearer results with fewer particles, enabling one to move from simply 'yes or no?' to exactly 'how much?' with the aid of an inexpensive, portable scanner."