Human immunodeficiency virus HIV-1 weakens the body's immune system by attacking healthy immune cells, leading to acquired immunodeficiency syndrome (AIDS, commonly known as AIDS). Control of HIV-1 remains a major global health challenge in developing countries that lack infrastructure and trained medical professionals. Traditional HIV-1 virus surveillance methods are more expensive and require the use of polymerase chain reaction (PCR). Furthermore, early detection of HIV-1 is key to preventing disease progression and transmission, but it requires long-term monitoring, which may be a burden for families who have to go to a clinic or hospital.

In a new study, to address this problem, Dr. Hadi Shafiee of Women's Hospital in Bregan, United States, and his team developed a portable, affordable mobile diagnostic tool that can be used to test and monitor HIV-1 in areas with limited medical resources, using nanotechnology, microchips, and three-dimensional printed cell phone accessories. This fast cell phone-based diagnostic platform represents a new way to diagnose acute virus infection, which may reduce the risk of virus transmission. In addition, it may also be used to detect early treatment failure. The findings were recently published in the journal Nature Communications with the title "DNA engineered micromotors powered by metal nanoparticles for motion based cellphone diagnostics ".

Source of image: Nature Communications, doi:10.1038/s41467-018-06727-8。

Using this diagnostic platform, the researchers were able to detect HIV-1 RNA present in one drop of blood. By monitoring the movement of DNA-modified polystyrene beads on its mobile phone, this device can detect HIV-1 RNA nucleic acids amplified by LAMP (loop- mediated isothermal amplification, ring-mediated isothermal amplification, a nucleic acid amplification reaction different from PCR, without using bulky or expensive equipment.

These researchers also assessed the specificity and sensitivity of this device. They found that within an hour, at a clinically relevant threshold of 1000 virus particles per milliliter, the device detected a specificity of 99.1% for HIV-1 and a sensitivity of 94.6%. It is worth noting that the total material cost of this microchip, cell phone accessories and reagents used at each test is less than $5.

Shafiee said that health workers in developing countries can easily use these devices to test and monitor HIV. Given the speed of such testing, a key decision on the next medical step could be taken on the spot. This will eliminate the burden of access to health clinics and provide individuals with a more effective HIV management tool.

First author of the paper Mohamed Shehata Draz said, “We may use this same technique as a fast, low-cost diagnostic tool for detecting other viruses and bacteria. This platform could help a lot of people around the world.”

Reference：

Mohamed Shehata Draz, Kamyar Mehrabi Kochehbyoki, Anish Vasan et al. DNA engineered micromotors powered by metal nanoparticles for motion based cellphone diagnostics. Nature Communications, Published Online: 16 October 2018, doi:10.1038/s41467-018-06727-8.