[15a-PA4-1~29] 3.12 Nanoscale optical science and near-field optics

[15a-PA4-13] Evaluation of Fluorescence Enhancement of Nanoparticles on the Bull’s Eye-type Plasmonic Chip by Fluorescence Microscopy

〇Mai Kanda¹, Eri Fujimoto¹, Keiko Tawa¹ (1.Kwansei Gakuin Univ.)

Keywords:plasmonic chip, Bull's eye, fluorescence

Plasmonic chip with Bull's eye structure is composed of hexagonal lattice array of concentric circles in which the cross section cut by a diameter shows a periodic structure. In this study, the fluorescent single nanoparticles on the Bull’s eye-type plasmonic chip were observed with a fluorescence microscope using two optical systems, epi-illumination and transmission illumination. The fluorescence intensity of the bright spots of single nanoparticles were evaluated for each distance from the center of the Bull's eye pattern. In the epi-illumination system, the enhanced fluorescence intensity of the particles did not change at any position within a Bull's eye pattern. On the other hand, in the transmission illumination system, the fluorescence intensity increased closer to the center of the Bull's eye pattern and the intensity at the center was found to be 8 times larger than that on a flat metal surface. Furthermore, it was found that the larger fluorescence intensity of the nanoparticles was observed at the center part of Bull’s eye array than that at the corner part of array. It is considered to be due to the plasmon modes propagated between the patterns of array.