Raman and Fourier Transform Infrared (FTIR) are vibrational spectroscopies that detect changes in a chemical bond’s polarisability (ie. The electron cloud around bond) and dipole moment, respectively. Both techniques are complimentary, and many vibrational modes are both Raman and IR active. In some cases, when there is a center of inversion in the crystal symmetry of the material, some vibrational bands will be only Raman active or IR active (not both – rule of mutual exclusivity).
The Renishaw Invia Reflex Raman microscope (Renishaw, Gloucestershire, UK) located within the SSSC is its only kind in Canada, as it also equipped with an IlluminatIR II FTIR microscope accessory (Smith’s Detection, Danbury, CT). In addition, the Invia Reflex microscope supports multiple laser wavelengths, along with sophisticated software that allows automatic switching of lasers. This allows multiple excitation wavelength Raman and FTIR spectroscopies to be obtained on the same spot with relative ease for the general user!
The Renishaw Invia Reflex Raman Microscope (Renishaw, Gloucestershire, UK) is fitted with a IlluminatIR II FTIR microscope accessory (Smith’s Detection, Danbury, CT) for measurement of Raman and FTIR spectra without having to move the sample to different spectrometers. Raman and FTIR and complimentary vibrational spectroscopy methods that are based on different principles but when combined almost all vibrational modes can be measured.
|Light Microscope||Leica DC2500M equipped with 5X (NA=0.12), 10X (NA=0.25), 20X (NA=0.40), 50X (NA=0.75), 100X (NA=0.85), 50X LWD (NA=0.40)|
|XYZ Motorized Stage||MS20 Encoded Stage, Renishaw, UK) with 100 nm step sizes which allows for the capability of very high spatial resolution mapping. Coupled with the correct laser excitation and objective, and spatial resolution can be better than 0.5 μm!|
|FTIR||IlluminatIR II FTIR accessory is equipped with a liquid nitrogen cooled MCT detector allows measurements in the 4000-650 cm-1 range with up to 4 cm-1 spectral resolution. The system uses a 15X (NA= 0.88) ARO objective (10-100 μm aperture) or a 36X diamond ATR objective (10-50 μm aperture).|
Solids: generally μg quantities are all that are needed
Liquids: 50-100 μL (Measurements are conducted through transparent material).
Raman Mapping – Samples should be relatively flat (microtome biological sections) to ensure good optical focus while mapping.