PROFILE The X-ray photoelectron spectroscopy, XPS, platform provides essential tools to investigate the chemical composition and structure of surfaces at nanoscale. Led by Andrey Shchukarev, the platform has developed unique methods that allow scientists to study everything from nanomaterials to living cells – and even uncover clues about how life’s building blocks may have formed.
No one believed me when I said, over 20 years ago, that it could be done.
"Today, we use our method daily,” says Andrey Shchukarev, manager of the XPS platform at Umeå University.
Arriving in Umeå in December 1999, Andrey joined the Department of Chemistry just as an X-ray photoelectron spectrometer – an advanced tool that can probe the invisible world of surfaces – was being installed. Today, more than two decades later, the XPS lab hums with activity as Andrey and his colleague, staff scientist Dmitry Shevela, study several samples on a daily basis.
Over time, and thanks to Andrey’s hard work, the XPS platform has grown into an internationally recognised resource for researchers across physics, chemistry, materials science, and life sciences: exploring the outermost nanometers of surfaces – from industry usages to fundamental research.
Andrey Shchukarev, manager of the XPS platform, demonstrates how he uses liquid nitrogen to cool samples before they are introduced into the spectrometer.
ImageRebecca ForsbergIn X-ray photoelectron spectroscopy, a beam of X-rays hits the sample, knocking out electrons from the surface atoms. The electrons reveal which elements are present: their chemical states and how they are distributed within just a few nanometers of the surface.
This level of detail is vital in many fields: XPS helps design better batteries, more durable coatings, and more efficient catalysts and sorbents. Here in Umeå, it also sheds light on how living cells interact with their surroundings.
Yet, to which Andrey contributed highlights that often only a fraction of XPS’s potential is used. “Most people use XPS just to check which elements are there,” Andrey says. “But with careful experiment design and analysis, you can learn so much more: nanostructure, electrical properties, even clues about how life’s building blocks may have formed.”
Two years ago, the lab welcomed a next-generation XPS system with a higher-intensity X-ray beam, allowing for faster measurements. They have also installed a new technique called Low Energy Inverse Photoemission Spectroscopy, LEIPS – likely the first of its kind in Sweden. LEIPS allows researchers to study the unoccupied electronic states of a material with high precision.
“The low-energy electrons are gentler than the X-rays and provide minimal damage to organic samples, while increasing the energy resolution,” Andrey explains.
Andrey Shchukarev with the new XPS-instrument that makes faster measurements possible.
ImageRebecca ForsbergJust like humans, bacteria consist mostly of water. However, water, cold, and high vacuum aren’t a good combination. “If we don’t freeze the bacterial samples quickly, they might explode,” Andrey explains.
No one thought it was possible to freeze bacteria so that they could be studied with XPS. But one of Andrey’s greatest contributions is a pioneering technique that has made the XPS platform in Umeå a go-to place for challenging biological and wet samples.
Andrey developed a fast-freezing process that cools wet samples at over 20 degrees per second down to minus 170 °C. This locks the biological structure in place, preserving the surface chemistry in almost a time-frozen state. Instead of drying out and cracking, which can happen in dry-freezing techniques, the surface of microorganisms remains intact.
A wet, fast-freezed sample in the XPS-instrument.
ImageRebecca Forsberg“With the cell surfaces intact, we realised that we could measure the amount of proteins, sugars and lipids on the cell surface. This is key for understanding how bacteria and other microorganisms react and interact with their environment, which is essential for biology and medicine,” Andrey says.
These measurements, described in a press release from 2022, were developed together with Madeleine Ramstedt and Jean-Francois Boily, both at the Department of Chemistry. Today, it is known as the Umeå method.
Madeleine Ramstedt, Associate Professor at the Department of Chemistry, and Andrey Shchukarev, together with Jean-François Boily at the Department of Chemistry, developed a method to measure sugars, proteins, and lipids on bacterial surfaces. The groundbreaking method, which laid the foundation for studying how bacteria interact with their environment — essential in biology and medicine — is today known as the Umeå method.
ImageMattias PetterssonThe unique approach of fast freezing has offered unexpected glimpses into the origins of life. In , Andrey and his colleagues discovered that -NHâ‚‚ groups – essential building blocks of amino acids – can form spontaneously under vacuum. When fast-frozen samples containing ammonium dry inside the XPS instrument, water is gradually removed from the iron oxide surface, triggering chemical changes in the ammonium.
“It was a big surprise to me that we could observe this,” says Andrey. “We saw that when a wet sample dries in the instrument, chemical changes take place that mimic steps believed to be crucial in the chemistry that led to life on early Earth.”
This observation suggests that simple, life-relevant molecules may have formed through natural processes on mineral surfaces – without the need for complex enzymes or catalysts.
Andrey inserts a sample in the XPS-instrument.
Image Rebecca Forsberg
Andrey displays samples sent from Silicon Valley, USA, to be analysed using XPS in Umeå.
– I’ve probably seen most of the minerals and substances that exist in the world, he says.
To create the X-rays used in analysing samples with XPS, high voltage is used.
Image Rebecca Forsberg
Andrey's office is filled with containers with samples.
Behind all these breakthroughs is Andrey’s quiet dedication and genuine fondness for his machines. “I consider these instruments my children,” he laughs. “I’ve given them personal names, after teachers and mentors who shaped my studies.”
Originally trained in inorganic chemistry in Leningrad (now St. Petersburg), Andrey began his career after PhD studies in industry but soon found himself longing for the lab. Umeå offered the freedom and resources he missed. “I have all I want and need here,” he says.
As retirement approaches, Andrey knows he will soon pass on the care of his ‘children’ to new hands. “I say hello every morning and thank them for the day as I leave – it will be hard not to spend time with these instruments every day,” he admits.
The legacy he leaves behind – a world-class XPS platform, a method that has changed how researchers see surfaces, and insights that stretch from nanomaterials to the chemistry of life – will continue to shape material science in Umeå.
What more can be done with XPS?
– Journal of Vacuum Science and Technology A (2025)
Molecules linked to life may have formed through natural processes on mineral surfaces
– The Journal of Physical Chemistry C (2011)
Pressrelease from Umeå University about the Umeå method
Method for analysing microorganisms’ surfaces gains international attention (2022)