BRUSSELS — VUB professor Gert Desmet has received the prestigious Tswett-Nernst Award. This international lifetime achievement award recognises his exceptional contributions to liquid chromatography, a separation technique that is essential for, among other things, the detection of pesticides, PFAS and medical biomarkers. A remarkable achievement, especially considering that Desmet is not formally trained as an analytical chemist.
Chromatography has existed for more than a hundred years. It is a technique used to separate complex chemical mixtures into individual components. A liquid or gas pushes a sample through a stationary medium (such as a tube or column filled with silica). Because molecules have different affinities for that medium, they travel through the system at different speeds, allowing individual substances to be accurately detected one after another. As a chemical process engineering graduate, Desmet encountered a practical problem during his PhD research. To solve it, he had to look beyond the boundaries of his own discipline. This led him to liquid chromatography.
"It turned out to be such a fascinating field with so much unexplored territory that I shifted my entire focus towards it," says Prof. Desmet. "Because I entered the field as an outsider, I was often able to make a significant impact through an original perspective."
That original approach soon became apparent in his work on pressureless chromatography. While industry pumps liquids through microscopic particles under extremely high pressures of up to 1,500 bar, Desmet demonstrated both theoretically and experimentally that this can also be achieved without such enormous pressure. "The idea of carrying out chromatography without pressure really made my name in the field. It was not always easy to establish myself as an outsider, but it all worked out very well in the end."
Micro-pillars on a silicon chip
One of his best-known breakthroughs is the reinvention of the chromatography column. Instead of filling a tube with a disorderly packing of loose particles, Desmet and his team designed silicon chips on which a highly ordered network of micro-pillars is created using lithographic etching techniques.
Because the particles in a traditional column are arranged irregularly, molecules all follow slightly different paths and emerge from the column in a dispersed sequence. With micro-pillars on a chip, all molecules are guided along exactly the same path. "The art of chromatography is to keep groups of identical molecules as close together as possible," Desmet explains. "With etching technology, we can fabricate that structure in a perfectly ordered way."
This invention formed the foundation of PharmaFluidics, a successful VUB spin-off that was later acquired by the international market leader Thermo Fisher Scientific. Whereas the pillars measured 5 micrometres when the company was founded, following a generation of 2.5 micrometres, the next step of 1.25 micrometres is now ready.
The key to the medicines of the future
The societal and industrial demand for faster and more accurate separation techniques is immense. Consider the identification of biomarkers for cancer screening or the analysis of complex human samples containing thousands of different proteins.
To solve these complex challenges even more quickly, Desmet has already turned his attention to another field: artificial intelligence. In collaboration with VUB AI experts Ann Nowé and Pieter Libin, he is working on integrating AI into chromatography.
"Selecting the right chromatographic conditions is an extremely complex problem into which industry invests vast amounts of money," Desmet explains. "If a laboratory receives a sample today and finds the right combination of parameters to separate the molecules within two weeks, that is considered good performance. But that still means two weeks of work involving multiple analysts and instruments. AI can help us dramatically accelerate that process."
Despite his decades-long career and this new lifetime achievement award, the researcher’s curiosity remains undiminished. "It is still wonderful to see how incredibly sharp the peaks passing the detector can be. The fact that molecules of the same type can remain so closely grouped together while flowing through a system continues to fascinate me."