, Volume 8, Issue 2, pp 591–598

Optimized Synthesis of PEG-Encapsulated Gold Nanorods for Improved Stability and Its Application in OCT Imaging with Enhanced Contrast


DOI: 10.1007/s11468-012-9438-1

Cite this article as:
Dinish, U.S., Goh, D., Fu, C.Y. et al. Plasmonics (2013) 8: 591. doi:10.1007/s11468-012-9438-1


Gold nanorods (GNRs) are synthesized with a surfactant template, which often poses toxicity issues for biomedical applications. In addition, blue shift of longitudinal surface plasmon resonance (LSPR) peak of GNR is an inherent problem that needs to be addressed for time-course studies. In this work, we resolve these issues by optimizing the encapsulation of GNRs with polyethylene glycol (PEG) where biocompatibility is improved by ∼20 % and blue shift over a period of 8 days is reduced from 20 nm in the case of CTAB-GNR to 2 nm for PEG-encapsulated GNR. The encapsulated GNRs were then bioconjugated for targeted dark-field imaging of cancer cells. As an application, we also demonstrate the contrast-enhancing capability of GNRs in optical coherence tomography (OCT) imaging of tumor xenograft where the LSPR closely matches the OCT excitation wavelength. Our study proves that incorporating GNRs enhances the contrast of tumor tissue interfaces along with a considerable broadening in OCT depth profile by six times.


Gold nanorodsPEG encapsulationLongitudinal surface plasmon resonanceCytotoxicityContrast enhancementOCT imaging

Copyright information

© Springer Science+Business Media, LLC 2012

Authors and Affiliations

  • U. S. Dinish
    • 1
  • Douglas Goh
    • 1
  • Chit Yaw Fu
    • 1
    • 4
  • Ramaswamy Bhuvaneswari
    • 2
  • Winston Sun
    • 3
  • Malini Olivo
    • 1
    • 4
    • 5
  1. 1.Bio-Optical Imaging Group, Singapore Bioimaging Consortium (SBIC)Agency for Science Technology and Research (A*STAR)SingaporeSingapore
  2. 2.Division of Medical ScienceNational Cancer Centre SingaporeSingaporeSingapore
  3. 3.Institute of MicroelectronicsAgency for Science, Technology and Research (A*STAR)Science Park IISingapore
  4. 4.Bio-Photonics Group, School of PhysicsNational University of IrelandGalwayIreland
  5. 5.Department of PharmacyNational University of SingaporeSingaporeSingapore