Interaction of Glutathione-Stabilized Gold Nanoclusters with Doxorubicin and Polycation

Abstract

Glutathione-capped gold nanoclusters display polyanionic properties that are manifested in the interaction with cationic species. The nanoclusters form complexes with doxorubicin with effective dissociation constant about 10 µM that increased by an order of magnitude in the presence of 0.15 M NaCl confirming electrostatic character of binding. Adsorption of polylysine arose an increase in the fluorescence of gold nanoclusters due to aggregation induced emission enhancement effect. Fluorescence of the complexes increased several-fold upon addition of up to 1 M of KCl suggesting contribution of non-Coulombic forces in the stabilization of aggregates of gold nanoclusters.