The first images of extraterrestrial molecules at atomic resolution

How did life come to Earth? One of the most accepted theories is that the fundamental components arrived at our planet in comets or asteroids. The clues may be in these bodies that are remnants of the formation of the solar system.

Now, a team of researchers from IBM Research and other international institutions have managed to obtain the , which hit Australia in 1969. This advance would allow the study of other similar bodies.

The scientists, who publish their findings in the journal Meteoritics and Planetary Science, recorded these images of the organic matter in the meteorite using ultra-high-resolution atomic force microscopy (AFM).

Thanks to AFM, they achieved, which -according to the authors- constitutes an advance, since this cannot be done with other common techniques. In addition, it allows the molecules present in meteorite samples, which are usually very scarce, to be studied in greater detail.

Trade He talked with Leo Gross and Katharina Kaiser, researchers from IBM Research, regarding the use of this technology, its contribution to planetary sciences and other fields of knowledge.

– What was the main objective of the study?

With this study, we aimed to show that high-resolution AFM, with its single-molecule sensitivity, can be used to complement commonly used analytical methods for investigating molecules from outer space. Demonstrating this for the first time in a well-characterized meteorite like the Murchison, where AFM can help identify individual molecules that might otherwise go undetected using only standard techniques.

– How does AFM technology work?

We are using non-contact frequency modulation AFM. This means that the tip of the AFM is attached to an oscillating sensor, in our case a qPlus sensor, and we detect changes in resonance frequency while scanning the tip in a plane above the molecule. Obtaining atomic resolution over molecules is possible thanks to a method that has been introduced here at IBM 13 years ago, which is the functionalization of the AFM tip with a single CO molecule. Thus, we can approach the molecule with the tip, close enough to detect the forces that arise due to the superposition of the wave functions of the electrons of the tip and the molecule. where the electron density is highest within the molecule. To ensure thermal stability and sample cleanliness, the microscope is kept in ultrahigh vacuum and at low temperatures (i.e., around 5 Kelvin). [-268.15]).

– Was this technology created by IBM?

Yes, scanning probe microscopy (SPM). The first was scanning tunneling microscopy (Scanning Tunneling Microscope or STM for its acronym in English), invented by Gerd Binnig and Heinrich Rohrer, two scientists who worked at IBM in Zurich, who were awarded the Nobel Prize in 1986 for it; and AFM was also invented at IBM 35 years ago. Later the AFM with tips functionalized with CO was also invented at IBM.

– For what other purposes can this technology be used?

AFM is very versatile and can be used to study different phenomena and surfaces. There are also multiple modes. It operates under vacuum, in air or in liquids, and length scales of scan ranges from millimeters to nanometers are investigated. Our AFM implementation is optimized for Some of its applications include semiconductor science and technology, molecular engineering, polymer physics, molecular biology, and more.

– And what other applications are they using it for?

In our group, for example, we analyze chemical reactions that we can trigger with the AFM probe and investigate them on an atomic scale. In another project, we investigated how certain properties of an individual molecule change by attaching or removing individual electrons.