A chip able to detect HIV one week after infection

Also available in: Español

The device patented by the CSIC, also allows to get the clinical results in less than five hours

By: JOANA OLIVEIRA

The future of the detection of HIV/AIDS fits in a half milimeter chip. A team in the Spanish National Research Council (CSIC) has developed a biosensor able to detect type 1 HIV in the first week after the infection. Experiments carried out with human serum, detect the antigen p24, a protein present in HIV-1 in concentrations 100.000 times lower than the current systems, which only detect the virus three or four weeks after infection. Another advantage is that the total time of the assay lasts four hours and 45 minutes, so the clinical results could be obtained on the same day. The research results have been published this Wednesday in the PLOS ONE magazine.

Early detection is key to prevent virus transmission , according to Priscila Kosaka, one of the creators of that technlogy. ¨The potential for infectivity of HIV in the first stage of contagion is much higher than in later stages¨, she explains. The researcher states that the sooner the antireroviral therapy starts the higher the improvement in the immunological control and the preservation of the cognitive function.

The biosensor combines silicon micro-mechanical structures with gold nanoparticles, that work with antibodies specific to p24. Serum is incubated on this sensor for one hour and at the end of the trial, HIV-antigens – if any – are trapped in a sandwich mode between the gold and silicon particles. Javier Tamayo, who works at the Institute of Microelectronic of the CSIC, explains that the combination of these two structures produces optical and mechanical signals of ¨extraordinary sensitivity¨to detect the virus. The blood has more than one thousand different proteins and trying to detect such a small quantity of antigens is like looking for a needle in the haystack¨says the researcher.

Scientists explain that silicon allows to develop inexpensive technologies, enabling large scale production of the biosensor at low cost, ¨It is a technology with potential to be taken to developing countries¨says Kosaka.

For the time being, the sensor is being used in early detection of some types of cancer , such as prostate cancer: the same chip is used, i.e. the physical part, and specific solutions are incubated on it, in order to detect the biomarkers that show the presence of carcinogenic cells. Kosaka had already developed a similar sensor in 2015 to detect tumors and diseases such as hepatitis, before the first symptoms appeared.

“The use of biosensors has not limits¨says Tamayo, who believes that in the future that technology can merge with mobile phones, so those devices would simplify dianostics.

This team of researchers has already started the bureaucratic procedures – which include tests at the Spanish Agency of Drugs and Health Products (AEMPS) as in the US Food and Drug Administration (FDA) to take the chip to hospitals and laboratories in several countries in the next three or four years.