Monodispersed and Monofunctionalized DNA-Caged Au Nano-Clusters with Enhanced Optical Properties for STED Imaging.
Small
; 20(29): e2400238, 2024 Jul.
Article
em En
| MEDLINE
| ID: mdl-38385800
ABSTRACT
The performance of Stimulated Emission Depletion (STED) microscopy depends critically on the fluorescent probe. Ultrasmall Au nanoclusters (Au NCs) exhibit large Stokes shift, and good stimulated emission response, which are potentially useful for STED imaging. However, Au NCs are polydispersed in size, sensitive to the surrounding environment, and difficult to control surface functional group stoichiometry, which results in reduced density and high heterogeneity in the labeling of biological structures. Here, this limitation is overcome by developing a method to encapsulate ultrasmall Au NCs with DNA cages, which yielded monodispersed, and monofunctionalized Au NCs that are long-term stable. Moreover, the DNA-caging also greatly improved the fluorescence quantum yield and photostability of Au NCs. In STED imaging, the DNA-caged Au NCs yielded ≈40 nm spatial resolution and are able to resolve microtubule line shapes with good labeling density and homogeneity. In contrast, without caging, the Au NCs-DNA conjugates only achieved ≈55 nm resolution and yielded spotted, poorly resolved microtubule structures, due to the presence of aggregates. Overall, a method is developed to achieve precise surface functionalization and greatly improve the monodispersity, stability, as well as optical properties of Au NCs, providing a promising class of fluorescent probes for STED imaging.
Palavras-chave
Texto completo:
1
Base de dados:
MEDLINE
Assunto principal:
DNA
/
Nanopartículas Metálicas
/
Ouro
Limite:
Humans
Idioma:
En
Ano de publicação:
2024
Tipo de documento:
Article