Cancer provokes mutations in cellular DNA. Detecting these changes in patients’ blood enables physicians to prescribe anticancer treatments that are better targeted and more effective. Detection, however, is only possible in specialized clinics and proves to be a long and costly process. Tackling this problem, scientists at the University of Fribourg have developed nanosensors that enable cheaper and faster detection of mutations.

Change affecting the DNA of cells is an essential step in both the onset and progression of cancer. Liquid biopsy (testing blood, urine, or other bodily fluids) can detect mutations that are present in tumorous tissue, as well as provide information about the type of cancer, its degree of malignancy, and most importantly its sensitivity or resistance to specific anticancer drugs. Because these analyses require specific equipment and specialized personnel, they can only be carried out in suitable medical labs. This explains why they are both expensive and time consuming.

A quick and cheap solution
To remedy this problem, Samet Kocabey, a researcher at the University of Fribourg who is part of Professor Curzio Rüegg’s team, devised nanosensors able to detect mutations in genetic code at extremely small concentrations. “These sensors then produce a fluorescent signal that can easily be processed by a flow cytometer, an instrument that is found in most hospitals and diagnostic laboratories,” Kocabey explained. “The analysis requires little actual hands-on work and can be done in a day as opposed to 3 to 5 days with current methods, and at a lower cost!”

This project enjoyed the support of the National Center of Competence in Research (PNR/NCCR) for Bio-Inspired Materials under the coordination of the University of Fribourg. Sarah Cattin, head of the Cell Analytics Facility, and Isabelle Gray, a PNR intern, also contributed to the study.

Towards a new generation of biosensors
These results are important for three reasons.

First, they simplify mutated DNA/RNA detection, making it accessible to a greater number of labs without the need to use expensive equipment or turn to specialized medical labs.

Secondly, it is worth noting that these nanosensors can also be used to detect non-mutated RNA, which broadens their application to molecular biomedical research.

Finally, they may pave the way for the development of rapid, simple and inexpensive clinical tests for detecting cancer mutations in tumorous tissues and blood samples in a much greater range of hospitals and diagnostic labs. Naturally this will benefit a larger number of patients.

This discovery was recently published in the scientific journal Biosensors and Bioelectronics. It was the subject of a patent application and reinforces the University of Fribourg’s position in the field of medical diagnostic technologies.

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Kocabey, S.; Cattin, S.; Gray, I.; Rüegg, C. Ultrasensitive Detection of Cancer-Associated Nucleic Acids and Mutations by Primer Exchange Reaction-Based Signal Amplification and Flow Cytometry. Biosensors and Bioelectronics 2025, 267, 116839. DOI: https://doi.org/10.1016/j.bios.2024.116839