Enhanced electric fields at pointed metal probes for high resolution near-field imaging
Two methodologies, aimed at increasing the sensitivity and resolution of near-field scanning optical microscopy (NSOM), were explored. The NSOM motifs employed in this study involve the generation of highly localized electric fields for spectroscopic interrogation. The first design incorporates a sharp gold tip to elicit an enhanced fluorescence response from dye-labeled polystyrene spheres. Second, a sample of standardized perforations in a gold film was produced to investigate the extent of electric field confinement around a platinum nanoparticle affixed to the aperture of a transmission-NSOM probe.