Related Experiment Videos
Near-field and confocal surface-enhanced resonance Raman spectroscopy at cryogenic temperatures
1Physikalische Chemie, Universität Siegen, 57068 Siegen, Germany Omicron NanoTechnology GmbH, 65232 Taunusstein, Germany. anger@chemie.uni-slegen.de
Journal of Microscopy
|March 19, 2003
Summary
A new microscope combines scanning near-field optics and confocal microscopy for high-resolution laser spectroscopy. This technique reveals single Rhodamine 6G molecule properties on silver nanoparticles at variable temperatures.
Area of Science:
- Physical Chemistry
- Spectroscopy
- Nanotechnology
Background:
- Laser spectroscopy requires high spatial resolution for detailed molecular analysis.
- Investigating single molecules provides unique insights into their properties.
Purpose of the Study:
- To develop a combined scanning near-field optical and confocal microscope for variable temperature laser spectroscopy.
- To investigate Rhodamine 6G (R6G) dye molecules on silver nanostructures.
Main Methods:
- Development of a hybrid microscope integrating scanning near-field optical microscopy (SNOM) and confocal microscopy.
- Optical excitation using an aperture probe or a focused laser spot.
- Recording Raman spectra from 300 cm⁻¹ to 3000 cm⁻¹ at temperatures down to 8.5 K.
Main Results:
- Raman spectra of Rhodamine 6G on silver nanoparticles/clusters were obtained.
- Observed Raman lines correlate with the adsorbed molecule's structure.
- Intensity fluctuations in spectral sequences down to 77 K indicate single molecule sensitivity.
Conclusions:
- The developed microscope enables high-resolution laser spectroscopy at variable temperatures.
- Single molecule sensitivity was achieved for Rhodamine 6G on silver nanostructures.
- The technique is valuable for studying molecular properties at the nanoscale.