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The research has been published in the journal 'Nature Nanotech' and highlighted in 'Nature'
Artificial atoms allow for magnetic resonance on individual cells
Researchers from the Institute of Photonic Sciences (ICFO) –an associate institute of the Universitat Politècnica de Catalunya · BarcelonaTech (UPC)–, in collaboration with the Spanish National Research Council (CSIC) and Macquarie University in Australia, have developed a new technique, similar to the MRI but with a much higher resolution and sensitivity, that has the ability to scan individual cells.
13/02/2013
In the article "Three-dimensional optical manipulation of a single electron spin", published in Nature Nanotech, and highlighted in Nature, ICFO researcher Romain Quidant explains how this was accomplished using artificial atoms, in the form of diamond nanoparticles doped with nitrogen impurity, to probe very weak magnetic fields such as those generated in some biological molecules.
Conventional MRI techniques register the magnetic fields of atomic nuclei in our bodies that have been previously excited by an external electromagnetic field. The collective response of all of these atoms makes it possible to diagnose and monitor the development of certain diseases. However, this conventional technique has a diagnostic resolution on a millimetric scale, and smaller objects do not give off enough of a signal for them to be measured.
The innovative technique proposed by the group led by Romain Quidant significantly improves the resolution at the nanometre scale (nearly one million times smaller than the millimetre), making it possible to measure very weak magnetic fields such as those created by proteins. "Our approach opens the door for the performance of magnetic resonances on isolated cells, which will offer new sources of information and allow us to better understand intracellular processes, enabling non-invasive diagnosis," explains Michael Geiselmann, the ICFO researcher who conducted the experiment. Until now, it has only been possible to reach this resolution in the laboratory, using individual atoms at temperatures close to absolute zero (approx. -273 degrees Celsius).
Individual atoms are structures that are highly sensitive to their environment, with a great ability to detect nearby electromagnetic fields. The challenge these atoms present is that they are so small and volatile that, in order to be manipulated, they must be cooled to temperatures near absolute zero. This complex process requires an environment that is so restrictive that it makes individual atoms unviable for potential medical applications. Artificial atoms used by Quidant and his team are formed by a nitrogen impurity captured within a small diamond crystal. "This impurity has the same sensitivity as an individual atom but is very stable at room temperature due to its encapsulation. This diamond shell allows us to handle the nitrogen impurity in a biological environment and, therefore, enables us to scan cells," argues Quidant.
To trap and manipulate these artificial atoms, researchers use laser light. The laser works like tweezers, leading the atoms above the surface of the object to study and extract information from its tiny magnetic fields.
The emergence of this new technique could revolutionise the field of medical imaging, allowing for substantially higher sensitivity in clinical analysis, an improved capacity for early detection of diseases and thus a higher probability of successful treatment.
This research has been possible thanks to the support of the private foundation Cellex Barcelona.
Research at the ICFO targets the forefront of science and technology based on light that can be of application in health, renewable energies, information technologies, security and industrial processes, among others. The Institute currently employs more than 250 researchers and PhD students, who work in more than 60 different laboratories. All of its research groups and facilities are housed in a purpose-built, 14,000 m2 building in the Mediterranean Technology Park, in the metropolitan area of Barcelona.
Conventional MRI techniques register the magnetic fields of atomic nuclei in our bodies that have been previously excited by an external electromagnetic field. The collective response of all of these atoms makes it possible to diagnose and monitor the development of certain diseases. However, this conventional technique has a diagnostic resolution on a millimetric scale, and smaller objects do not give off enough of a signal for them to be measured.
The innovative technique proposed by the group led by Romain Quidant significantly improves the resolution at the nanometre scale (nearly one million times smaller than the millimetre), making it possible to measure very weak magnetic fields such as those created by proteins. "Our approach opens the door for the performance of magnetic resonances on isolated cells, which will offer new sources of information and allow us to better understand intracellular processes, enabling non-invasive diagnosis," explains Michael Geiselmann, the ICFO researcher who conducted the experiment. Until now, it has only been possible to reach this resolution in the laboratory, using individual atoms at temperatures close to absolute zero (approx. -273 degrees Celsius).
Individual atoms are structures that are highly sensitive to their environment, with a great ability to detect nearby electromagnetic fields. The challenge these atoms present is that they are so small and volatile that, in order to be manipulated, they must be cooled to temperatures near absolute zero. This complex process requires an environment that is so restrictive that it makes individual atoms unviable for potential medical applications. Artificial atoms used by Quidant and his team are formed by a nitrogen impurity captured within a small diamond crystal. "This impurity has the same sensitivity as an individual atom but is very stable at room temperature due to its encapsulation. This diamond shell allows us to handle the nitrogen impurity in a biological environment and, therefore, enables us to scan cells," argues Quidant.
To trap and manipulate these artificial atoms, researchers use laser light. The laser works like tweezers, leading the atoms above the surface of the object to study and extract information from its tiny magnetic fields.
The emergence of this new technique could revolutionise the field of medical imaging, allowing for substantially higher sensitivity in clinical analysis, an improved capacity for early detection of diseases and thus a higher probability of successful treatment.
This research has been possible thanks to the support of the private foundation Cellex Barcelona.
About the ICFO
The Institute of Photonic Sciences (ICFO) was created in 2002 by the Government of Catalonia and the UPC. The ICFO is a centre of research excellence devoted to the sciences and technologies of light that has a triple mission: to conduct frontier research, to train the next generation of scientists and technologists and to provide knowledge and technology transfer. As part of the ICFO’s goal to usher in advances made at the ICFO for the benefit of society, the Institute actively promotes the creation of spin-off companies by ICFO researchers.Research at the ICFO targets the forefront of science and technology based on light that can be of application in health, renewable energies, information technologies, security and industrial processes, among others. The Institute currently employs more than 250 researchers and PhD students, who work in more than 60 different laboratories. All of its research groups and facilities are housed in a purpose-built, 14,000 m2 building in the Mediterranean Technology Park, in the metropolitan area of Barcelona.
+ information:
"Three-dimensional optical manipulation of a single electron spin", published in Nature Nanotech by Michael Geiselmann, Mathieu L. Juan, Jan Renger, Jana M. Say, Louise J. Brown, F. Javier García de Abajo, Frank Koppens and Romain Quidant.
"Three-dimensional optical manipulation of a single electron spin", published in Nature Nanotech by Michael Geiselmann, Mathieu L. Juan, Jan Renger, Jana M. Say, Louise J. Brown, F. Javier García de Abajo, Frank Koppens and Romain Quidant.
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