Silane-modified lanthanide complexes for integration into hybrid coatings and nanoparticles : thermal sensing applications and live cell labeling

Sedmak, Ivan (author), Bolje, Aljoša (author), Kljun, Jakob (author), Podlipec, Rok (author), Kokot, Hana (author), Nemec, Sebastjan (author), Kralj, Slavko (author), Rodič, Peter (author), Golobič, Iztok (author), Pajk, Stane (author)

Temperature sensing at the micro- and nanoscale remains a significant challenge due to the limitations of conventional techniques in spatial resolution and invasiveness. Here, we report the development of luminescent, temperature-sensitive coatings and nanoparticles based on a newly synthesized europium (Eu) complex integrated into a composite poly(methyl methacrylate)-siloxane-silica (PMMA-siloxane silica) matrix. The Eu complex, identified as the most promising candidate among three lanthanide complexes, was functionalized with silyl ethers via copper-catalyzed azide-alkyne cycloaddition and successfully incorporated into thin PMMA-siloxane silica films on glass surfaces and within silica nanoparticles. These materials exhibited strong thermal responsiveness, chemical stability, and suitability for high-resolution temperature sensing. Furthermore, Eu-loaded silica nanoparticles showed a distinct fluorescent signal and multiplexing capability in live-cell confocal microscopy and were internalized by lung epithelial cells (LA-4 cell line), highlighting their potential as bioimaging probes for localized intracellular temperature sensing. Although some photobleaching was observed under prolonged excitation, the materials demonstrated sufficient chemical and mechanical stability, making them promising for luminescent temperature sensing and live-cell imaging. These results establish the developed Eu-based hybrid materials as robust, non-invasive luminescent probes for high-resolution thermal sensing and cellular imaging.

• Language: English
• Keywords: temperature sensing, silica nanoparticles, europium complex, Eu complex, photostability, PMMA-siloxane silica coating, thermometry, photostability
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FS - Faculty of Mechanical Engineering; FFA - Faculty of Pharmacy; FKKT - Faculty of Chemistry and Chemical Technology
• Publication status: Published
• Publication version: Version of Record
• Year: 2026
• Number of pages: 13 str.
• Numbering: Vol. 589, art. 122904
• PID: 20.500.12556/RUL-182668
• UDC: 621.7+621.9
• ISSN on article: 1873-3255
• DOI: 10.1016/j.ica.2025.122904
• COBISS.SI-ID: 250457603
• Publication date in RUL: 20.05.2026

Record is a part of a journal

• Title: Inorganica Chimica Acta
• Publisher: Elsevier
• ISSN: 1873-3255
• COBISS.SI-ID: 23179013

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: senzorji, zaznavanja temperature, nanodelci v matrici silike, nanodelci