title: Highly sensitive detection of proteins and bacteria in aqueous solution using surface-enhanced Raman scattering and optical fibers.
abstract: 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.
authors.affiliation: Department of Electrical Engineering, University of California, Santa Cruz, California 95064, United States.
authors.forename: Xuan
authors.initials: X
authors.lastname: Yang
authors.forename: Claire
authors.initials: C
authors.lastname: Gu
authors.forename: Fang
authors.initials: F
authors.lastname: Qian
authors.forename: Yat
authors.initials: Y
authors.lastname: Li
authors.forename: Jin Z
authors.initials: JZ
authors.lastname: Zhang
mesh_terms: D015374:Biosensing Techniques / Q000379:methods*; D045304:Cytochromes c / Q000032:analysis*; D053768:Metal Nanoparticles / Q000737:chemistry; D009113:Muramidase / Q000032:analysis*; D055100:Optical Fibers; D020592:Shewanella / Q000302:isolation & purification*; D012834:Silver / Q000737:chemistry; D013059:Spectrum Analysis, Raman / Q000379:methods*; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D012834:Silver; D045304:Cytochromes c; D009113:Muramidase