Scientists led by Hana Lísalová from the Division of Optics have made a significant step towards a breakthrough in the field of optical fibre sensors. For the first time, they have succeeded in combining two advanced technologies – antifouling polymer brushes and optical fibres, thereby significantly increasing their reliability. This innovative approach paves the way for accurate detection of biomolecules even in challenging environments such as blood plasma.
Scientists led by Hana Lísalová from the Division of Optics have made a significant step towards a breakthrough in the field of optical fibre sensors. For the first time, they have succeeded in combining two advanced technologies – antifouling polymer brushes and optical fibres, thereby significantly increasing their reliability. This innovative approach paves the way for accurate detection of biomolecules even in challenging environments such as blood plasma.
The new method, developed in collaboration between a team from the Institute of Physics of the Czech Academy of Sciences and the Italian Institute of Applied Physics "Nello Carrara" within the international NABABAS consortium, uses a special antifouling terpolymer brush (ATB) that minimizes unwanted adsorption of biomolecules and allows selective binding of target analytes. The researchers demonstrated the concept in a model antibody detection and proved the high sensitivity and robustness of the newly modified sensors. The results were published by the journal Biomaterials Science, and even made it to the cover of the issue.
"Our team has developed a method that allows optical fibre sensors to operate with high accuracy even in challenging biological environments such as blood plasma. The key to success was not only the advanced nanobrush technology, but also the collaboration within the team and with colleagues in Italy. Together, we have managed to overcome a long-standing obstacle in the field of biosensing and open the way to wider practical use of these sensitive sensors," says Hana Lísalová, head of the Laboratory of Functional Biointerfaces, and adds: "Many thanks go to the PhD students in our team, especially Marketa Vrabcová, for her tenacity and perseverance to bring such a complex interdisciplinary work to a successful conclusion."
Nanobrushes protect sensors from biofouling
Optical fibre sensors are one of the cutting-edge technologies for bioanalytical applications. Their use in real biological conditions has so far been very limited due to the lack of efficient post-modification strategies that would allow a high recognition capability of selected biomolecules on the one hand and on the other hand prevent the attachment of any other biomolecules. It is this obstacle that has been overcome with the polymer nanobrush, a principle with which the team of the Laboratory of Functional Biointerfaces has extensive experience and has achieved a number of worldwide successes. They were able to synthesize this brush directly on the sensitive region of a long-period grating fibre.
The newly developed antifouling terpolymer brush (ATB) is composed of carboxybetaine methacrylamide, sulfobetaine methacrylamide and N-(2-hydroxypropyl)methacrylamide. Its excellent antifouling properties stem from a combination of several factors:
· High hydrophilicity – the brush surface interacts strongly with water, forming a protective layer that prevents the attachment of unwanted biomolecules.
· Electroneutrality – the positive and negative charges in the polymer structure balance each other, minimizing the electrostatic attraction of unwanted biomolecules.
· Biocompatibility and functionalization – the polymer brush can be easily customized for selective detection of specific biomolecules.
Confirmed efficacy in blood plasma
The functionality of the terpolymer brush on optical fibre sensor surfaces has been validated by advanced methods such as scanning electron microscopy, fluorescence microscopy and label-free
optical biodetection experiments. Tests have shown that sensors with this coating significantly reduce non-specific adsorption of biomolecules even during long-term contact with blood plasma. At the same time, they enable functional binding of antibodies and detection of target biomolecules in real-time with high selectivity.
"Optical fibre sensors have enormous potential in diagnostics and environmental analysis. The development of effective antifouling coatings, such as ATB, represents an important step towards their wider use in practice. Investments in advanced technologies in this area not only push the boundaries of current science but also respond to fundamental societal challenges, such as accessible and accurate diagnostics or ensuring food and water safety," says Alexandr Dejneka, head of the Division of Optics of the Institute of Physics.
New opportunities in medicine and biotechnology
The combination of antifouling and biorecognition properties make ATB nanobrushes a fundamental innovation in the field of biosensorics. They can be used, for example, in the rapid diagnosis of infectious diseases, monitoring biomarkers in blood, or in food safety.
This method paves a new avenue to the development of highly sensitive biosensors that can be used in the field as well as in clinical practice, significantly expanding the possibilities of modern diagnostics and analytical chemistry.