Plasmonic biodegradable gold nanoclusters with high NIR-absorbance for biomedical imaging

Robert Stover, Avinash Murthy, Sai Gourisankar, Golay Nie, Miguel Martinez, Thomas Truskett, Konstantin Sokolov, Keith Johnston

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations

Abstract

Gold plasmonic nanoparticles are receiving attention for a variety of types of NIR optical biomedical imaging including photoacoustic imaging. Herein we present a novel method to assemble equilibrium gold nanoclusters from 5 nm primary gold nanospheres, which exhibit high near-infrared (NIR) absorbance and subsequently fully dissociate back to primary particles, which has the potential to enable renal clearance. The nanoparticle assembly is manipulated via controlling colloidal interactions, specifically electrostatic repulsion and depletion attraction. The charge on the primary ∼5 nm gold nanospheres is tailored via place exchange reactions with a variety of biocompatible ligands such as citrate, lysine and cysteine. The primary particles form clusters upon addition of a biodegradable polymer, PLA(1k)-b- PEG(10k)-b-PLA(1k), followed by controlled solvent evaporation. The cluster size may be tuned from 20-40 nm in diameter by manipulating the gold and polymer concentrations along with the solvent evaporation extent. Salt is also added to increase the NIR absorbance and reduce the nanocluster size by reducing polymer adsorption. The adsorption of the polymer onto the Au surfaces effectively quenches the nanoclusters. High NIR absorption facilitates photoacoustic imaging, even for the small cluster sizes. In response to acidic cellular pH environments, the polymer degrades and the clusters dissociate back to primary particle on the order of 5 nm, which are small enough for renal clearance.

Original languageEnglish (US)
Title of host publicationColloidal Nanoparticles for Biomedical Applications IX
PublisherSPIE
ISBN (Print)9780819498687
DOIs
StatePublished - 2014
EventColloidal Nanoparticles for Biomedical Applications IX - San Francisco, CA, United States
Duration: Feb 1 2014Feb 4 2014

Publication series

NameProgress in Biomedical Optics and Imaging - Proceedings of SPIE
Volume8955
ISSN (Print)1605-7422

Other

OtherColloidal Nanoparticles for Biomedical Applications IX
Country/TerritoryUnited States
CitySan Francisco, CA
Period2/1/142/4/14

Keywords

  • Biodegradable
  • Biomedical imaging
  • Clearable
  • Gold nanoclusters
  • Photoacoustic
  • Plasmonic
  • Protein adsorption

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Biomaterials
  • Atomic and Molecular Physics, and Optics
  • Radiology Nuclear Medicine and imaging

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