A host–guest approach to ratiometric pH sensing using upconversion nanoparticles
Herein, we present a pH-sensitive nanoplatform based on Tm<sup>3+</sup>/Yb<sup>3+</sup> co-doped upconversion nanoparticles (UCNPs) functionalized with β-cyclodextrin (β-CD) and a pH-responsive nitrobenzoxadiazole dye modified with adamantane (NBD-Ad). The host-guest interaction between β-CD on the UCNP surface and Ad on NBD-Ad enables a stable, water-dispersible ratiometric pH sensor. Upon 980 nm excitation, the UCNPs emit in the UV and blue regions, which overlap with the pH-dependent absorption of NBD-Ad. This overlap induces selective quenching of UV and blue emissions <i>via</i> inner filter effect (IFE). The red emission (650 nm) remains stable and is used as an internal reference for ratiometric sensing. The sensor shows a ratiometric response (blue/red) over a pH range of 8.0-11.0 with high reproducibility. The nanoplatform demonstrates excellent reusability and selectivity even in the presence of interferents.
Authors
- Andréa Simone Stucchi de Camargo (ORCID: https://orcid.org/0000-0001-8352-2573)
- Marylyn Setsuko Arai (ORCID: https://orcid.org/0000-0003-1278-5274)
- Fabio Rizzo (ORCID: https://orcid.org/0000-0003-4045-2653)
- Bart Jan Ravoo (ORCID: https://orcid.org/0000-0003-2202-7485)
- Ivo Rosenbusch
Institutions
- Federal Institute For Materials Research and Testing (DE)
- Schott (Germany) (DE)
- Universidade de São Paulo (BR)
- University of Milan (IT)
- University of Münster (DE)
Publication Details
- Journal
- Nanoscale Advances
- Published
- 2025-01-01
- DOI
- https://doi.org/10.1039/d5na00145e
- Primary Topic
- Luminescence Properties of Advanced Materials
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Deutscher Akademischer Austauschdienst
- Deutsche Forschungsgemeinschaft
- Fundação de Amparo à Pesquisa do Estado de São Paulo
- Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
- Conselho Nacional de Desenvolvimento Científico e Tecnológico