Imperial scientists create USB device for HIV test

Scientists at Imperial College London and spinout company DNA Electronics have developed a HIV test that uses a drop of blood on an adapted USB stick to test for the virus.

(Credit: Imperial College)
(Credit: Imperial College)

A small volume of blood is placed on a spot on the USB stick, which contains a mobile phone chip. If HIV is detected, this triggers a change in acidity, which the chip then transforms into an electrical signal. The signal is sent via the USB stick to a computer, which displays the results through a custom program. It is hoped the test could be used by HIV patients to monitor their own treatment, in the same way that many diabetics do.

Current tests for HIV involve sending blood samples to a lab and can take up to three days, according to the researchers. The new device not only tests for the presence of the virus, but can also help patients monitor their viral levels, and can indicate whether anti-retroviral treatment is effective.

“HIV treatment has dramatically improved over the last 20 years – to the point that many diagnosed with the infection now have a normal life expectancy,” said Dr Graham Cooke from Imperial’s Department of Medicine, senior author of the research.

“However, monitoring viral load is crucial to the success of HIV treatment. At the moment, testing often requires costly and complex equipment that can take a couple of days to produce a result. We have taken the job done by this equipment, which is the size of a large photocopier, and shrunk it down to a USB chip.”

In the latest research, the technology was used to test 991 blood samples, producing results in an average time of 20.8 minutes, and performing with 95 per cent accuracy. DNA Electronics is already using the same technology to develop a test for detecting bacterial and fungal sepsis and antibiotic resistance, while the Imperial team is exploring the possibility of using the same principles to test for other viruses such as hepatitis.