R+D CSIC

A system to detect bacteria and virus through their mass and mechanical rigidity

The system is based on a nanodetector developed by scientists at the Microelectronics Institute of Madrid (IMM-CSIC). It is more sensitive than current methods and will allow and earlier detection of pathogens.

Between the initial infection and the moment when the virus has replicated enough to be at detectable levels, there is a lapse of time. In the case of the HIV, for instance, the virus is not detected by current methods until three weeks after the infection. This is because the levels are too low (there are not enough copies of the virus) for the current methods, which are not sensitive enough.

The longest the lapse of time, the higher the risk to spread the infection as the carrier, not being aware of the situation, will not take any prevention. Something similar happens with bacteria and other pathogens. This situation has especially dramatic consequences in the case of emergent and virulent diseases, such as the Ebola or Nile viruses.
 
To overcome this problem, a new method has been developed by scientists at the Microelectronics Institute of Madrid (IMM-CSIC). It is a new technique that allows the detection and identification of bacteria and virus through their mass and mechanical rigidity, with high sensitivity and selectivity.

The system, called nanomechanical spectrometry, is based on a mechanical nanodetector whose structure is similar to a tiny springboard. It is very small and a thousand times thinner than a human hair. “The springboard is excited to vibrate at several modes, similarly as a guitar string would do. The frequency of each vibration mode changes abruptly when a bacteria lands on the springboard surface”, explains Javier Tamayo, a CSIC scientist at the Microelectronics Institute of Madrid (IMM-CSIC).

In the case of the VIH, scientists think it could be detected the first week after the infection with this system

The system is similar to the mass spectrometry method, with the difference that it measures not only mass but also the mechanical rigidity, and it is more sensitive. Therefore, it can detect pathogens at lower concentration levels. In the case of the VIH, scientists think it could be detected the first week after the infection.

This technology can analyze several pathogens in a single sample. For doing that, it uses an electric field and pressure gradients, to generate ionized drops, each one of them is in turn divided until every virus or bacteria is isolated inside a single drop, which arrives to the springboard. The drops arrive one after the other to the springboard, so the system can detect consecutively several pathogens.

An algorithm developed by the scientists allows simultaneously infer the mass and the mechanical rigidity of each pathogen landing on the springboard.

This technology has been successfully tested for the detection of E. coli bacteria. Results were recently published in Nature Communications.  

“The work is a conceptual demonstration of this technology” says Javier Tamayo. “Now the system is being developed for its implementation in hospitals, in the frame of the VIRUSCAN European project, led by our group and with the contribution of 8 research groups from all Europe”.

The results of the study have been patented. The spin-off company NanoDrams has arrived to an agreement with the CSIC to acquire the license of the patent to keep on with the development.

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