IN-SITU ANALYSIS OF ADSORBED MOLECULES BY MICROSURFACE-ENHANCED RAMAN-SCATTERING

Surface-enhanced Raman microprobe spectroscopy (micro-SERS) and surfac e-enhanced resonance Raman microprobe spectroscopy (micro-SERRS) of or ganic molecules adsorbed on a metal surface is reviewed. Advantages an d applications of these new vibrational spectroscopic methods particul arly for in situ study of the chemical identity, structure, orientatio n, chemical and electrochemical reaction of biomolecules, organic poll utants, dioxins (furans) and surfactants adsorbed at charged metal sur faces are discussed. Different applications show that this spectroscop ic technique is a powerful in situ method to study the liquid/solid in terface at high resolution. Moreover, the high enhancement factor of t he Raman scattering intensity creates a new technique for obtaining hi gh-resolution vibrational spectra of organic molecules from dilute aqu eous solution in an electrochemical cell down to 10(-9) mol dm-3. It p ermits the acquisition of Raman spectra from electrode spots down to 1 mum in size or other forms of microsamples approaching the subpicogra m level.