NEAR-FIELD SURFACE-ENHANCED RAMAN SPECTROSCOPY OF DYE MOLECULES ADSORBED ON SILVER ISLAND FILMS

Abstract We report the combined use of scanning near-field optical microscopy and surface-enhanced Raman scattering (SERS) to obtain spectral, spatial and chemical information of molecular adsorbates with subwavelength lateral resolution. Near-field SERS spectra of cresyl fast violet and rhodamine 6G on silver substrates are obtained with short exposure times (less than 100 s) and a signal-to-noise ratio of >20. Spectra from as few as ≈300 molecules or less than 10 −2 monolayers adsorbed on about ten silver nanoparticles can be recorded using 200 nm tip apertures. For the near-field spectra, a local Raman enhancement factor of 10 13 or greater can be derived from a comparison with fluorescence measurements.

[1]  James H. Jett,et al.  SINGLE-MOLECULE DETECTION OF RHODAMINE 6G IN ETHANOLIC SOLUTIONS USING CONTINUOUS WAVE LASER EXCITATION , 1991 .

[2]  A. Otto,et al.  Surface enhanced Raman scattering , 1983 .

[3]  David N. Batchelder,et al.  Development of a scanning near-field optical probe for localised Raman spectroscopy , 1995 .

[4]  E. Betzig,et al.  Near-Field Spectroscopy of the Quantum Constituents of a Luminescent System , 1994, Science.

[5]  R. Dasari,et al.  Single Molecule Detection Using Surface-Enhanced Raman Scattering (SERS) , 1997 .

[6]  D. Zeisel,et al.  Pulsed laser‐induced desorption and optical imaging on a nanometer scale with scanning near‐field microscopy using chemically etched fiber tips , 1996 .

[7]  Paul F. Barbara,et al.  Polarization-Modulation Near-Field Scanning Optical Microscopy of Mesostructured Materials , 1996 .

[8]  Volker Deckert,et al.  Optical spectroscopy and laser desorption on a nanometer scale , 1997 .

[9]  E. Betzig,et al.  Near-field spectroscopy of single molecules at room temperature , 1994, Nature.

[10]  Steven R. Emory,et al.  Probing Single Molecules and Single Nanoparticles by Surface-Enhanced Raman Scattering , 1997, Science.

[11]  Bernard Humbert,et al.  Subwavelength Raman spectroscopy , 1997 .

[12]  P. Hildebrandt,et al.  Role of water in bacteriorhodopsin's chromophore: resonance Raman study , 1984 .

[13]  Lukas Novotny,et al.  Facts and artifacts in near-field optical microscopy , 1997 .

[14]  T. D. Harris,et al.  Breaking the Diffraction Barrier: Optical Microscopy on a Nanometric Scale , 1991, Science.

[15]  C. Licoppe,et al.  Imaging and local infrared spectroscopy with a near field optical microscope , 1996 .

[16]  Din Ping Tsai,et al.  Raman spectroscopy using a fiber optic probe with subwavelength aperture , 1994 .

[17]  Hans D. Hallen,et al.  Nano‐Raman Spectroscopy and Imaging with a Near‐Field Scanning Optical Microscope , 1996 .

[18]  W. Denk,et al.  Optical stethoscopy: Image recording with resolution λ/20 , 1984 .

[19]  D. Higgins,et al.  Excitonic transitions in J-aggregates probed by near-field scanning optical microscopy , 1995 .