Silica-coated gold nanostars for combined surface-enhanced Raman scattering (SERS) detection and singlet-oxygen generation: a potential nanoplatform for theranostics.

Journal Article (Journal Article)

This paper reports the synthesis and characterization of surface-enhanced Raman scattering (SERS) label-tagged gold nanostars, coated with a silica shell containing methylene blue photosensitizing drug for singlet-oxygen generation. To our knowledge, this is the first report of nanocomposites possessing a combined capability for SERS detection and singlet-oxygen generation for photodynamic therapy. The gold nanostars were tuned for maximal absorption in the near-infrared (NIR) spectral region and tagged with a NIR dye for surface-enhanced resonance Raman scattering (SERRS). Silica coating was used to encapsulate the photosensitizer methylene blue in a shell around the nanoparticles. Upon 785 nm excitation, SERS from the Raman dye is observed, while excitation at 633 nm shows fluorescence from methylene blue. Methylene-blue-encapsulated nanoparticles show a significant increase in singlet-oxygen generation as compared to nanoparticles synthesized without methylene blue. This increased singlet-oxygen generation shows a cytotoxic effect on BT549 breast cancer cells upon laser irradiation. The combination of SERS detection (diagnostic) and singlet-oxygen generation (therapeutic) into a single platform provides a potential theranostic agent.

Full Text

Duke Authors

Cited Authors

  • Fales, AM; Yuan, H; Vo-Dinh, T

Published Date

  • October 2011

Published In

Volume / Issue

  • 27 / 19

Start / End Page

  • 12186 - 12190

PubMed ID

  • 21859159

Pubmed Central ID

  • PMC4022297

Electronic International Standard Serial Number (EISSN)

  • 1520-5827

International Standard Serial Number (ISSN)

  • 0743-7463

Digital Object Identifier (DOI)

  • 10.1021/la202602q


  • eng