Highly sensitive detection of proteins and bacteria in aqueous solution using surface-enhanced Raman scattering and optical fibers

Anal Chem. 2011 Aug 1;83(15):5888-94. doi: 10.1021/ac200707t. Epub 2011 Jul 1.


We report the detection of the proteins lysozyme and cytochrome c as well as the live bacterial cells of Shewanella oneidensis MR-1 in aqueous solutions with sensitivities order(s) of magnitude higher than those previously reported. Two highly sensitive surface-enhanced Raman scattering (SERS)-based biosensors using optical fibers have been employed for such label-free macromolecule detections. The first sensor is based on a tip-coated multimode fiber (TCMMF) with a double-substrate "sandwich" structure, and a detection limit of 0.2 μg/mL is achieved in protein detections. The second sensor is based on a liquid core photonic crystal fiber (LCPCF) with a better confinement of light inside the fiber core, and a detection limit of 10(6) cells/mL is achieved for the bacteria detection. Both SERS biosensors show great potential for highly sensitive and molecule-specific detection and identification of biomolecules.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Biosensing Techniques / methods*
  • Cytochromes c / analysis*
  • Metal Nanoparticles / chemistry
  • Muramidase / analysis*
  • Optical Fibers*
  • Shewanella / isolation & purification*
  • Silver / chemistry
  • Spectrum Analysis, Raman / methods*
  • Water / chemistry


  • Water
  • Silver
  • Cytochromes c
  • Muramidase