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 (Au<inf>6</inf>-Au<inf>16</inf> and Au<inf>5</inf>-Au<inf>14</inf>) responsible for the observed luminescent properties. The very small (≈1.2nm) synthesized cluster complexes are water soluble and suitable to be used for the conjugation of biomolecules (through the terminal COO<sup>-</sup> 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.

SANTIAGO GONZALEZ, B., Vázquez Vázquez, C., Blanco Varela, M., Gaspar Martinho, J., Ramallo López, J., Requejo, F., et al. (2015). Synthesis of water-soluble gold clusters in nanosomes displaying robust photoluminescence with very large Stokes shift. JOURNAL OF COLLOID AND INTERFACE SCIENCE, 455, 154-162 [10.1016/j.jcis.2015.05.042].

Synthesis of water-soluble gold clusters in nanosomes displaying robust photoluminescence with very large Stokes shift

SANTIAGO GONZALEZ, BEATRIZ
;
2015

Abstract

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 (≈1.2nm) 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.
Articolo in rivista - Articolo scientifico
Cluster-cluster complexes; Large Stokes shifts; Luminescent gold clusters; Nanosomes; Surfaces, Coatings and Films; Electronic, Optical and Magnetic Materials; Biomaterials; Colloid and Surface Chemistry
English
2015
455
154
162
none
SANTIAGO GONZALEZ, B., Vázquez Vázquez, C., Blanco Varela, M., Gaspar Martinho, J., Ramallo López, J., Requejo, F., et al. (2015). Synthesis of water-soluble gold clusters in nanosomes displaying robust photoluminescence with very large Stokes shift. JOURNAL OF COLLOID AND INTERFACE SCIENCE, 455, 154-162 [10.1016/j.jcis.2015.05.042].
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/123169
Citazioni
  • Scopus 19
  • ???jsp.display-item.citation.isi??? 16
Social impact