A new class of nontoxic nanoparticle tags based on surface enhanced Raman scattering

X. M. Qian, D. Ansari, Shuming Nie

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


The advance of nanotechnology has boosted the development of ultra-sensitive biosensors for biomedical applications. Most recently, optical detection based biosensors have been demonstrated in medical imaging and diagnosis employing nanocrystals such as fluorescent quantum dots (QDs) and plasmon resonant metal nanoparticles to achieve femto-molar detection. An intriguing but far less explored approach for biological diagnostics relies on an emerging ultrasensitive technology - surface enhanced Raman scattering (SERS) spectroscopy. We have developed a stable SERS nano-tag by grafting hydrophilic polymer to gold nanoparticle-dye molecule complexes to preserve the spectral signature and fully control the aggregation states. The light-emitting power and scattered light of both QDs and SERS nano-tags have been recorded under the same experimental conditions using dark field microscope, fluorometer, and Raman instrument. A comparison in brightness, sensitivity level, and quantum efficiency between SERS nano-tags and near infrared (NIR) QDs has been assessed on both bulk colloidal solution and single particle measurements. Well-designed SERS nano-tags exhibit excellent advantages over NIR QDs.

Original languageEnglish (US)
Title of host publicationColloidal Quantum Dots for Biomedical Applications II
StatePublished - 2007
Externally publishedYes
EventColloidal Quantum Dots for Biomedical Applications II - San Jose, CA, United States
Duration: Jan 20 2007Jan 23 2007

Publication series

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


OtherColloidal Quantum Dots for Biomedical Applications II
Country/TerritoryUnited States
CitySan Jose, CA


  • Surface enhanced Raman scattering (SERS) spectroscopy
  • Ultra-sensitive biosensor

ASJC Scopus subject areas

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


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