Molecular close-up

Weizmann Institute scientists present a new method for imaging a single electron

For several decades, MRI scans have been an essential means of identifying a multitude of diseases, and as a result, saving countless lives. Simply put, this technology makes it possible to produce a coherent image of the inside of the body, by measuring the density of water molecules. The image is obtained with a resolution of 1 cubic millimeter - an excellent degree of separation if our aim is to check if there is, for example, a tear in the meniscus in the knee. But what about the structure of a single molecule? The size of such a molecule is around 5 cubic nanometers - that is, it is about 10 trillion times smaller than the highest resolution that the most modern MRI scanner is capable of reaching, so - on the face of it - this is an impossible task. But for Dr Amit Finkler From the Department of Chemical and Biological Physics at the Weizmann Institute of Science - this is the mission. In the article thatRecently published, Dr. Finkler, research student Dan Yudilevich and their partners from the University of Stuttgart, Germany - Dr. Rainer Stöhr and Dr. Andrei Denisenko - managed to complete another step in this direction, when they demonstrated a new method for imaging single electrons. The method is indeed in the initial development stage, but It is possible that in the future it will be applied for imaging at the molecular level - which may revolutionize the development of new drugs and the characterization of quantum materials.

The setup the researchers use: a thin membrane made of diamond 30 microns thick with an average of one sensor at the top end of each column. The top image - magnification 2,640 times, the bottom - 32,650 times
The setup the researchers use: a thin membrane made of diamond 30 microns thick with an average of one sensor at the top end of each column. The top image - 2,640 times magnification, the bottom - 32,650 times

MRI was and still is a breakthrough method, but in some cases it has drawbacks. For example, in order for it to work properly, a relatively large sample is needed - at least a few hundred billion water molecules - and as a result the displayed output is a kind of average of smaller components - which the machine is unable to recognize. In most types of diagnoses - the average is actually the desired and optimal result. But in other cases - for example, in drug development - work is required on as small a sheet as possible, which will provide accurate results. Beyond that, when averaging so many different components - some of the information may fall through the cracks, thus even preventing the discovery of important processes that happen on an extremely small scale. For this purpose, the scientists propose molecular close-up photography.

The new method can locate the exact position of a single electron by applying a magnetic field and rotating it around a synthetic diamond, which is used as a quantum sensor

What would a more accurate imaging device look like, capable of working on an extremely small scale? Dr. Finkler, Yudilevich and their partners developed a method that can locate the exact position of a single electron by applying a magnetic field and rotating the field around a synthetic diamond, which is used as a quantum sensor. In fact, it is not the diamond itself that acts as a sensor, but a tiny defect in it - the size of a single atom - It is called a "nitrogen-vacancy center". Due to the sensor's atomic size, it is particularly suited to distinguishing the changes occurring near it, and due to its quantum nature, it can distinguish between a single electron and a cluster of electrons. Due to its properties, it is particularly suitable for measuring the position of an electron in space isolated with an extraordinary level of precision, which provides us with a sneak peek into the imaging technologies of the future.

"It will be possible to use the new method we developed," says Dr. Finkler, "to provide doctors and scientists with an additional and complementary point of view - to the existing imaging methods." The development of such a tool may allow scientists to closely investigate the structure of important molecules, thus paving the way for new discoveries The scientists envision a future in which we can use the new method to image a wide variety of molecules, which will hopefully reveal more layers of the holy molecular trinity: structure, function and interactions.

Multidisciplinary

Dr. Amit Finkler first came to the Weizmann Institute of Science as a bachelor's graduate. He completed his second and third degrees at the institute in the laboratory of Prof. Eli Zeldov, in the Faculty of Physics, before going to the University of Stuttgart - where he did his post-doctoral research. Five years ago he returned to Rehovot and founded His own laboratory - in the Faculty of Chemistry.

"I'm a physicist," says Dr. Finkler, "but working in the Faculty of Chemistry creates unique opportunities for the research we carry out in my laboratory. We have physicists, but there are also chemists and engineers. It's an interesting combination, and the possibility of combining different research methods and disciplines is necessary for the type The science I'm interested in, I like to aim lenses, enjoy cryogenic burns, and now I'm spraying engineered molecules on our diamonds."

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