120th General Meeting of the KCS

Type Poster Presentation
Area Physical Chemistry
Room No. Exhibition Hall 2+3
Time 10월 20일 (금요일) 13:00~14:30
Code PHYS.P-119
Subject Homogeneous gold colloidal surfaces optimal for metal-enhanced fluorescence
Authors Junghyun Song, jaebeom lee, Daedu Lee, YOONSOO PANG*
Division of Physical Chemistry, Gwangju Institute of Science and Technology, Korea
Abstract When fluorophores exist in close proximity to plasmonic metal nanoparticles, the fluorescence of dye molecules is strongly enhanced. Exact mechanisms of metal-enhanced fluorescence (MEF) are not yet fully understood, but the locally increased electric field around metal nanoparticles and the plasmon coupled emission of metal nanoparticles have been proposed as those. The MEF shows strong dependence on the properties of the surface plasmon resonance, which is strongly dependent on the size and shape of metal nanoparticles and the metal-fluorophore distance. In this work, the gold colloidal surfaces (GCFs) were synthesized by attaching homogeneous gold colloidal nanoparticles to glass substrates which were prepared by the seeded growth method. The absorption spectrum and the SEM images of GCFs were measured and the GCFs showed high homogeneity in size and the extinction spectra were shifted from visible to near-infrared region depending on the particles size. For the fluorescence enhancement measurements, the GCFs with the 125 nm diameter were found as optimal for the MEF with some NIR dyes. For the study of enhancement mechanisms, time-resolved fluorescence spectroscopy with time-correlated single photon counting system and FDTD simulation were also used.
E-mail songjh121@gist.ac.kr