25 April 2025 / News, Research

New spectroscopic methods for the quantitative detection of functional groups on the nanoparticles surface

The combination of nanoparticles with biologically active molecules such as antibodies offers promising applications in the diagnosis and treatment of various diseases. In order to design these so-called bioconjugated nanoparticles in a precise manner, it is important to obtain quantitative information about the number of functional groups on the nanoparticle surface prior to bioconjugation reaction.

Researchers from the SNI network have now developed two new methods to quantify functional surface groups of metal oxide nanoparticles. The researchers from the Department of Chemistry at the University of Basel have tested the two methods, which are based on fluorescence and UV-Vis spectroscopy, using a model system with hafnium oxide nanoparticles.

The first quantification method is based on the attenuation of a fluorescence signal, the other on the disappearance of a UV-Vis signal. Both methods showed a similar accuracy and precision. Moreover, the use of the second method can be reliably extended to other types of inorganic nanoparticles and surface ligands. The experimental work was carried out by SNI doctoral student Elizaveta Maksimova from Prof. Dr. Jonathan de Roo's team. The team recently published the results in the scientific journal Small Structures.

Original publication:

Elizaveta Maksimova, David E. Salazar Marcano, Jonathan De Roo 
Quantification of Azides on the Surface of Nanoparticles: Toward Precise Bioconjugation 
Small Struct. 2025, https://doi.org/10.1002/sstr.202500083