The whispering galleries born as acoustic phenomenon.The reflection of sound within a gallery oval or semi-oval allows two people talk at opposite positions as if they were one beside the other.But with the advent of nanotechnology, it soon became clear that with the light is that these galleries are more promising – the phenomenon that occurs with sound waves also occurs with light waves.
Using this end, researchers have just create a super-sensor capable of detecting even the smallest viruses known.
Light waves are directed into the interior of a tiny glass sphere, where they resonate at a frequency very accurately.Just like playing a violin in string changes its frequency, even the smallest object that enter the gallery glass changes the frequency of the light in a measurable way.Thus the apparatus functions as a sensor very accurate.
In this configuration, it is possible to detect large viruses, such as influenza responsible for.But smaller viruses such as polio caused, for example, be pass unnoticed.
A group of New York University, in the United States, managed to increase sensor sensitivity by more than 70 times by simply adding some “pollutants” within the gallery resonant.Instead of interfering with the measurements, the gold nanospheres that researchers have introduced have created what scientists called “plasmonic spots”, areas where the light is coupled to waves of electrons, known as surface plasmons.
This hybrid photonic sensor / plasmon not only able to detect the tiny MS2 virus – the lowest RNA virus which is known – as was also able to determine the weight of the virus from the interference it causes the resonant beam.According to the researchers, the next step is to adapt the sensor it detects proteins and disease markers in the blood.