Project SMURFnano: Standardised measurements of surface functionalities on nanoparticles

07/10/2024

• Challenge
• Objectives
• Methods
• Partners

Engineered nanoparticles with various surface functionalities are routinely fabricated for industrial applications in medicine, chemistry, electronics, and energy conversion and storage. The function, performance, interaction with biological species, and environmental fate are largely determined by nanoparticle surface functionalities. Thus, reliable surface characterisation methods are vital for quality and stability control of engineered nanoparticles and to meet increasing safety concerns.

The goal of this metrology project is to perform research to support standardisation in surface chemical analysis of nanomaterials. Therefore, quantitative methods and procedures for measuring surface functionalities and the thickness and composition of coatings will be developed and validated by interlaboratory comparisons performed in the project. The results will be used to develop and provide tests and reference materials, reference data and methods and contribute to new guidance documents.

The project follows the “Putting (more) Science into Standards” initiative of the European Commission. Methods will be developed in the laboratory and optimised by the project partners, and then validated in international interlaboratory comparisons. The results will be made available to the nanotechnology community as reference data and methods as well as test and reference materials. These results will be also used for the development of new guidance documents for ISO, IEC, and OECD.

European Partnership on Metrology, co-financed from European Union’s Horizon Europe Research and Innovation Programme and by the Participating States.

Engineered nanoparticles with various chemical composition and surface chemistry have reached a multi-billion market with applications in, e.g. medical diagnostic, sensing, catalysis, energy conversion and storage, and opto-electronics. Standards for measuring nanoparticle size and shape have been increasingly developed in recent years. These standards, however, do not address nanoparticle surface chemistry which largely determines the dispersibility, stability, and performance of engineered nanoparticles. Therefore, industry and regulators are increasingly asking for validated and standardised measurement protocols to support the manufacturing, quality control, and safe use of nanoparticles. To meet these demands, in SMURFnano, currently available methods for quantifying nanoparticles surface functionalities will be explored, further developed, validated, and standardised. Thereby, standardised protocols for quantifying nanoparticle surface functionalities with advanced methods like X-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS), and quantitative nuclear magnetic resonance spectroscopy (qNMR) will be developed.

In parallel, simple and less expensive optical and electrochemical methods will be assessed that are often utilised in manufacturing process and stability control and the quality management of functional nanoparticle-based products. The SMURFnano consortium will organise two international interlaboratory comparisons (ILCs) under the auspice of VAMAS (Versailles Project on Advanced Materials and Standards) on the following topics: (i) measurement of the shell thickness of core-shell nanoparticles with electron spectroscopy and (ii) measurement of the functional group surface concentration on nanoparticles. The outcomes of these ILCs will be used for developing and providing reference methods, reference data, and test and reference materials for the nanotechnology community to underpin the development of quality control methods in nanomaterial production. The project will contribute to the standards development work of different technical committees of ISO and of IEC as well as of OECD. In addition, the scientific output of SMURFnano will initiate future standardisation projects according to the PSIS (“Putting (more) Science into Standards”) initiative of the European Commission.

Project partners

1. Istituto Nazionale di Ricerca Metrologica (INRIM), Italy
2. RI.SE, Sweden
3. Evonik, Germany
4. Institut “Jozef Stefan”, Slovenia
5. PolyAn, Germany
6. Universität Wien, Austria
7. Freie Universität Berlin, Germany
8. Physikalisch-Technische Bundesanstalt, Germany
9. LGC Ltd., United Kingdom
10. National Physical Laboratory, United Kingdom
11. National Research Council Canada, Canada

Funding

The project 23NRM02 SMURFNano has received funding from the European Partnership on Metrology, co-financed from the European Union’s Horizon Europe Research and Innovation Programme and by the Participating States.