The defined chemical compositions and atomic structures make the molecular-like gold nanoclusters fundamentally interesting because structure-function correlations could be established. This category of nanomaterials also received much attention due to their exciting physicochemical properties, chemical stability and flexibility for further functionalizations. Our group has been working on the control of core-ligand interfacial bonding via a multi-dentate approach, with a focus on the corresponding impacts on the electrochemical activity and near IR luminescence. In this report, we describe the quantum efficiency enhancement of the near IR emission from prototype thiolate stabilized Au nanoclusters via a combined thermo and thiol-etching treatment. Up to ten fold enhancement has been achieved with the emission max beyond 700 nm, a preferred spectrum window with less autofluorescence and other cellular interference. The as-synthesized, thermo-optimized, and PEGlated Au nanoclusters chemical and luminescence properties are evaluated in a wide pH range, and in a range of common buffers and cell media. Cell internalization of Au nanocluster at different dosage and incubation duration are studied with confocal microscopy. Quantification/ analysis reveal heterogeneous distribution in different subcellular organelles. The pathway is proposed based on further analysis of internalization kinetics. Nucleus entry is attributed to passive diffusion and validated by co-localization of nucleus stain/dye and z-stack analysis.

Heterogeneous distribution and cell internalization dynamics of Au nanoclusters with enhanced near IR luminescence

247th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.