Development of near-field laser ablation inductively coupled plasma mass spectroscopy for sub-micrometric analysis of solid samples

Abstract : A near field laser ablation inductively coupled plasma mass spectroscopic method (NF-LA-ICPMS) was developed for chemical analysis at sub-micrometric scale. This analytical technique combines a nanosecond laser, an Atomic Force Microscope (AFM), and a high resolution ICP-MS. In order to improve the spatial resolution of the laser ablation process, the near field enhancement effect was applied by illuminating the apex of a conductive sharp tip of the AFM by a laser beam. The laser energy was kept below the sample ablation threshold, and a distance of a few nanometers (5 to 30 nm) was maintained between the tip and the surface sample. The interaction between the illuminated tip and the sample surface enhances locally the incident laser irradiance and leads to the ablation process.