Synthesis of water-soluble gold clusters in nanosomes displaying robust photoluminescence with very large Stokes shift
This paper reports a novel procedure using nanosomes, made of bola-hydroxyl and mercapto-palmitic acids, for the production of gold clusters with robust luminescent emissions and very large Stokes shifts. It shows that these results cannot be explained by the currently accepted mechanism based on li...
| Autores: | , , , , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2015 |
| País: | Argentina |
| Institución: | Consejo Nacional de Investigaciones Científicas y Técnicas |
| Repositorio: | CONICET Digital (CONICET) |
| Idioma: | inglés |
| OAI Identifier: | oai:ri.conicet.gov.ar:11336/5474 |
| Acceso en línea: | http://hdl.handle.net/11336/5474 |
| Access Level: | acceso abierto |
| Palabra clave: | Luminescent Gold Clusters Clustercluster Complexes Large Stokes Shifts Nanosomes https://purl.org/becyt/ford/1.4 https://purl.org/becyt/ford/1 |
| Sumario: | This paper reports a novel procedure using nanosomes, made of bola-hydroxyl and mercapto-palmitic acids, for the production of gold clusters with robust luminescent emissions and very large Stokes shifts. It shows that these results cannot be explained by the currently accepted mechanism based on ligand-to-metal charge transfer absorptions involving electron-rich ligands attached to the cluster core. Exhaustive characterization of the cluster samples using Mass Spectrometry, HR-TEM/STEM, XPS, EXAFS, and steady-state and time-resolved luminescence allows to deduce that a mixture of two cluster sizes, having non-closed shell electronic configurations, are firstly generated inside the nanosome compartments due to the difference in bonding strength of the two types of terminal groups in the fatty acids. This initial bimodal cluster size distribution slowly evolves into very stable, closed-shell Au cluster complexes (Au6-Au16 and Au5-Au14) responsible for the observed luminescent properties. The very small (≈1.2 nm) synthesized cluster complexes are water soluble and suitable to be used for the conjugation of biomolecules (through the terminal COO− groups) making these systems very attractive as biomarkers and offering, at the same time, a novel general strategy of fabricating stable atom-level quantum dots with large Stokes shifts of great importance in many sensor applications. |
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