Absolute Counting Method with Multiplexing Capability for Estimating the Number Concentration of Nanoparticles Using Anisotropically Collapsed Gels

0562009 - ÚIACH 2023 RIV US eng J - Journal Article
Hlaváček, Antonín - Křivánková, Jana - Brožková, Hana - Weisová, Julie - Pizúrová, Naděžda - Foret, František
Absolute Counting Method with Multiplexing Capability for Estimating the Number Concentration of Nanoparticles Using Anisotropically Collapsed Gels.
Analytical Chemistry. Roč. 94, č. 41 (2022), s. 14340-14348. ISSN 0003-2700. E-ISSN 1520-6882
R&D Projects: GA ČR(CZ) GA21-03156S
Institutional support: RVO:68081715 ; RVO:68081723
Keywords : absolute quantification * counting * photon-upconversion * fluorescence * nanoparticles
OECD category: Analytical chemistry; Analytical chemistry (UFM-A)
Impact factor: 7.4, year: 2022
Method of publishing: Limited access

The presented method is suitable for estimating the number concentration of nanoparticles and their bioconjugates. The method benefits from well-defined immobilization of nanomaterials in anisotropically collapsed agarose gel. Once immobilized, the nanoparticles are imaged by a microscope and counted. The number of counted nanoparticles is then used for estimating the number concentration. The accuracy and precision of the method were characterized by the samples of photon-upconversion nanoparticles. By analyzing the brightness of the emission from single diffraction-limited spots, it was possible to analyze also the content of UCNP clusters. The detection of extremely weak emitters was proved. The method supports several microscope imaging modalities such as photon-upconversion, fluorescence, dark-field, and bright-field microscopy. The applicability of these modalities is demonstrated by imaging UCNPs, dye-doped fluorescent silica nanoparticles, CdSe/ZnS quantum dots, and submicron silica particles. Thus, the method is not limited to a particular nanomaterial or imaging modality type. The method was developed for aqueous dispersions of nanoparticles and utilized the agarose gel to provide a well-defined immobilization of nanomaterials. However, the gels are not limited to only agarose or aqueous dispersions. Therefore, the method can be likely extended to other types of solvents and gel matrices. Interestingly, agarose contains only light elements such as carbon, oxygen, hydrogen, and a small amount of sulfur. Therefore, the method is potentially compatible with TEM, which can provide an even more detailed analysis.
Permanent Link: https://hdl.handle.net/11104/0334437