Frankfurt 2006 – wissenschaftliches Programm

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MO: Molekülphysik

MO 71: Dynamics and Spectroscopy at Interfaces

MO 71.6: Vortrag

Freitag, 17. März 2006, 11:55–12:10, H12

Surface Enhanced Raman Spectroscopy (SERS) with Nano-Structured Gold Surfaces — •M. Sackmann, T. Balster, and A. Materny — International University Bremen, Bremen

Raman spectroscopy is a common tool for qualitative and quantitative chemical analysis of molecules even in a mixture of different substances. Although, the unique identification of adenine molecules is possible via their vibrational lines, high concentrations (mmol/l) are needed for qualitative results due to the low scattering cross section for non-resonant excitation. The intensity of the Raman spectra is amplified by the use of the Surface Enhanced Raman Scattering (SERS) technique. While the use of silver sols only results in a limited reproducibility of the Raman line intensities, nano-structured gold surfaces, if used as SERS-active substrates, in principle should combine the high sensitivity with better reproducibility. For this purpose, we have produced gratings of gold dots on Si(001) surfaces by means of electron beam lithography. The distance between the gold nanostructures was varied between 350 to 370 nm and for the diameters of the gold dots values between 50 to 320 nm were chosen. The samples are characterized by reflection spectroscopy, to determine the resonance of the grating structure. Recent measurement results with Raman microscopy of adenine (ppm concentrations) on these structures will be presented.