SERS Microscopy: Laser Illumination Effects

Hadamard transform SERS microscopy of pyridine at Ag electrodes with focused 514.5-nm, 532.0-nm, and 632.8-nm excitation is reported. It is shown that focused 514.5-nm and 532.0-nm laser excitation produces photochemical or photothermal damage at roughened Ag electrodes. Photo-damage limits the spatial resolution of SERS microprobe and raster-scanned point imaging techniques which use focused green excitation at Ag electrodes.