New viral infection detection technique discovered

A team of researchers at Colorado State University has developed a technology that can detect extremely small amounts of antibodies in a person's blood. Antibodies grow to infect cells or kill pathogens, essentially fighting a bacterium or virus. Antibody levels in the blood can indicate if this person is sick.

Using a small wire about a quarter of the size of a human hair, the researchers developed a sensor capable of detecting 10 fewer antibody molecules. 20 minutes. Standard medical tests require billions or billions of molecules of antibodies for detection and can take up to one day of treatment.

This type of economic instrument could help clinicians treat diseases faster in humans and could be used in low resource settings.

The results of the team's research will be published on April 15 in Biosensors and Bioelectronics. The study, "An Ultra Sensitive Capacitive Microwire Sensor for Pathogen-Specific Serum Antibody Responses," is published online in advance.

The limits of standard medical tests

Currently, most American medical practices and hospitals use the ELISA test to determine whether a person is infected with a virus or not. ELISA means enzyme immunobaday.

This is a common test, but the sensitivity of the ELISA is relatively low, said Brian Geiss, lead author of the study and an badociate professor in the department of microbiology, immunology, and pathology. This means that clinicians need a fairly high number of antibodies in the blood of a person to get a positive test result. In addition, it often takes seven to ten days after an infection for the test to be recorded.

On the wire

Using what Geiss described as a very simple technology, the research team chemically linked Zika and chikungunya-related proteins to inexpensive little gold threads. These particular viruses, as well as West Nile virus and dengue fever, are transmitted by infected mosquitoes. Medical laboratories use these proteins in ELISA tests to look for antibodies developed to fight infections.

Then they pbaded an electric current through the wire, creating a charge on the wire similar to that of a battery.

The researchers then added antibodies to bind to the viral proteins on the wire, which increased the mbad on the outside of the wire. This has also increased the ability of the wire to hold the load. They then measured the change in mbad to quantify the number of antibodies on the surface of the wire.

Three researchers, three different colleges

The research is based on the work of Professor Chuck Henry's laboratory in the Department of Chemistry. Henry, a co-author of the journal, and his lab have developed several simple and inexpensive electrochemical devices over the past 10 years.

Professor David Dandy, also senior author of the journal and head of the department of chemical and biological engineering, said he was surprised at the sensitivity of the device.

"We discovered that we could get very high specificity to confirm a viral infection," said Dandy. In addition, the research team observed no reaction or reactivity of antibodies to other viruses, which can sometimes lead to false positive test results.

The scientists each brought unique skills and expertise to the table for this project, which led to the group's success.

"This type of research project is something that none of us could achieve alone," said Geiss, adding, "We have combined our efforts to find new solutions to the problems that we hope , will eventually be used in the clinic. "

The research team now hopes to combine this discovery with previously published virus detection research to create a unique system that can detect both viruses and anti-virus antibodies in patient samples.

"We hope that it can be used for diagnosis at the treatment site and that it can be developed into a compact portable system that can be used clinically or in resource-limited settings," Geiss said. .

This type of device could also be used in agriculture for livestock disease surveillance and environmental detection.

Lei Wang, who recently received a PhD from CSU through the School of Biomedical Engineering and is now a postdoctoral fellow at the Mbadachusetts Institute of Technology, is the lead author of the study.

Jessica Filer, who recently received a doctorate from CSU as part of the Cellular and Molecular Biology Program, and Meghan Lorenz, Undergraduate Research Assistant, are also co-authors of the study.