Analytical Sciences

Fluorescence Enhancement of Nanoraspberry Hot-spot Source Composed of Gold Nanoparticles and Aniline Oligomers

Takamasa KINOSHITA,* Dung Quang NGUYEN,* Tomoaki NISHINO,* Hidenobu NAKAO,** Hiroshi SHIIGI,* and Tsutomu NAGAOKA*

*Department of Applied Chemistry, Osaka Prefecture University, 1-2 Gakuen, Naka, Sakai, Osaka 599-8570, Japan
**National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan

In this study, we examined raspberry-shaped organic/inorganic hybrid structure for potential development of a nanoantenna system capable of detecting and labeling biomolecules. The structure is characterized by a high density of gold nanoparticles (AuNPs) separated by closely packed aniline oligomers that serve as a linkage between adjacent particles. In particular, the structure was based on repeated sequences of AuNP-aniline oligomer-AuNP in a three-dimensional arrangement, which enabled the creation of optical hot spots that can hold multiple molecules. We examine the expression of such features by focusing on the structure and characteristics of the hybrid. We demonstrate that these optical hot spots enhance the dye fluorescence without quenching. As a result, we were able to create a nanoantenna structure enabling the efficient use of light.

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