New smartphone-based test can detect HIV in seconds

Scientists have developed a novel smartphone-based test that uses a single drop of blood from a patient to detect HIV in just 10 seconds.
The test could provide doctors and carers with a virtually instantaneous way of diagnosing someone with HIV.
"We have developed this 10-second test for HIV using existing smartphone technology, but it could in theory be used for a range of viruses, such as Zika or Ebola, potentially meaning that we can identify serious outbreaks before they become full epidemics," said Vince Emery, professor at University of Surrey in the UK.
The mobile test uses surface acoustic wave (SAW) biochips, which are based on microelectronic components found in smartphones.

The disposable quartz biochips are extremely fast because they do not require complex labelling, amplification or wash steps, and a pocket-sized control box reads out the SAW signal and displays results electronically.
Early detection of HIV is vital to help contain potential outbreaks, but existing tests require complex analysis equipment and long waiting times for results.

The team first optimised SAW biochips and capture coatings to detect model HIV antibodies and recombinant antigens (anti-p24 and p24 respectively).
This was then used to test real patient samples, using differential measurements, in order to achieve high specificity and sensitivity within seconds.
The study, published in the journal Scientific Reports, opens up the potential of consumer electronics to cut lengthy test waiting times, giving patients on the spot access to potentially life-saving treatment and supporting more timely public health interventions to prevent disease outbreaks.

Early diagnosis and access to antiretroviral treatment increases life-expectancy by 10 years, reduces infant mortality by 76 per cent and in pregnant women can almost completely prevent transmission to their baby, researchers said.
"This is an exciting breakthrough that lays the foundations for future clinical studies and product development," said Rachel McKendry, professor at University College London in the UK.
"If successful, this platform technology could revolutionise rapid HIV diagnosis and deliver major health and economic benefit to millions of people worldwide," McKendry said.