Dynamic Raman/SERS Imaging of Living Cells by Slit-Scanning Microscopy

The powerful analytical capability of Raman spectroscopy has not been fully utilized to image biological samples because of the small cross-section of Raman scattering. We have applied a slit-scanning technique for Raman observation of biological samples to improve the image acquisition rate in order to trace biological activities of a cell. The slit-scanning Raman microscope illuminates a sample with a line-shaped focus and measure Raman spectra from multiple points in the sample simultaneously. This parallel detection of Raman spectra allows us to image the sample over two orders of magnitude faster than confocal Raman microscopy. Although slit-scanning microscopy may not exceed nonlinear Raman spectroscopy in the image acquisition rate, it has an advantage in analyzing samples with the hyperspectral imaging capability.