Cheap, simple test detects a single virus in urine straight from the source
As Zika has reminded the world, viruses are still a major threat to a healthy populace. One of the key components to battling them is detection, but methods to do so can often be costly and complicated, which means they're not always available to the populations that most need them. Researchers at the University of Texas at Austin (UT) have joined the ranks of others seeking to make affordable virus detection more accessible to the masses by developing a method that uses an electrode thinner than a human cell to pick up the destructive bugs in urine.
To create and test the new method, the researchers put the wee wire in mouse urine. They then added a mix of enzymes and antibodies to the urine that are attracted to the particular virus being targeted – in this case, it was the murine cytomegalovirus (MCMV), which belongs to the same family as the herpes virus. Once a molecule of the virus, a molecule of the antibody, and a molecule of the enzyme attach to each other and bump into the wire, a surge of electricity is created. By monitoring this surge, the researchers can tell if a particular virus is present.
Because the method screens for only one virus at a time, it has the advantage of reducing false negatives that can be triggered by similar viruses or other contaminants. It can also detect viruses in relatively small concentrations. The UT team also reports that the method can use "urine straight from a person or animal," which means it's not necessary to purify the sample as can be the case with other detection methods.
Even though the technique – which is known as a digital electrochemical immunosensor – was only used with the MCMV virus, the researchers feel it could be developed to detect other viruses with more work.
"The ultimate goal is to build a cheap, easy-to-use device to take into the field and measure the presence of a virus like Ebola in people on the spot," says Jeffrey Dick, a chemistry graduate student and co-lead author of the study. "While we are still pretty far from this, this work is a leap in the right direction."
One of the challenges the researchers face as they seek to further develop the technology is that right now the electrodes lose sensitivity because other biological materials eventually build up on their surface, blocking their ability to detect the virus for which they're intended. Should the team be able to overcome this challenge, and build a rugged field-ready container of the technology, virus detection across the globe could certainly get more than a wee bit better.
The team's paper was published this week in the journal Proceedings of the National Academy of Sciences.
Source: University of Texas