Researchers at the University of Texas (Austin, TX, USA) have developed a new method to rapidly detect a single virus in a urine sample. At present, the highly selective sensor detects only one virus, though the researchers suggest that it could be adapted to detect Ebola, HIV and Zika viruses.
“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,” commented Jeffrey Dick, co-lead author of the study. “While we are still pretty far from this, this work is a leap in the right direction.”
At present, the two most commonly used virus detection methods have drawbacks that limit their use in the field. One method can detect only higher concentrations of viruses, and the other requires samples to be purified of contaminants before testing. By contrast, the new method is able to detect single virus particles, and urine can be tested without prior purification.
In a proof-of-concept demonstration, the team tested the new technique on murine cytomegalovirus, from the same family as the herpes virus. An electrode was placed in the biological sample – mouse urine – and added to this was a solution of enzymes and antibodies that ‘stick’ to the virus of interest. When the virus-enzyme-antibody complex touches the electrode, this leads to a spike in electric current.
The researchers highlight that while the sensor is a promising new method of virus detection, it still requires some refinement – for example, the electrodes currently become less sensitive over time. Additionally, they hope to design a casing device for the virus sensor that will be both compact and hard-wearing, in order for the sensor to be useful in a range of environments in and outside of the clinical setting.
Sources: Dick JE, Hilterbrand AT, Strawsine LM, Upston JW, Bard AJ. Enzymatically enhanced collisions on ultramicroelectrodes for specific and rapid detection of individual viruses. PNAS. doi:10.1073/pnas.1605002113 (2016) (Epub ahead of print); http://news.utexas.edu/2016/05/23/making-virus-sensors-cheap-and-simple