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-118
Subject Metal-enhanced Fluorescence Observed with Homogeneous Silver Colloidal Films
Authors Daedu Lee, jaebeom lee, Junghyun Song, YOONSOO PANG*
Division of Physical Chemistry, Gwangju Institute of Science and Technology, Korea
Abstract The emission of dye molecules is largely enhanced by noble metal nanoparticles due to locally-enhanced electric fields and surface plasmon coupled emission (SPCE), which is in general called metal-enhanced fluorescence (MEF). MEF has been extensively applied to many disciplines including biological sensing and imaging, and organic optoelectronics but the details of the MEF are not yet clear. In this study, we fabricated homogeneous silver colloidal films (SCFs) composed of silver nanoparticles in a wide range of diameter (70-200 nm). The extinction spectra of homogeneous SCFs showed spectral shifts depending on the size of particles and much narrower bandwidth than those of inhomogeneous silver island films. DCM and Rh700 dyes were used to seek for the optimal conditions for the efficient MEF with each SCF. The SCFs with SPR bands overlapped or slightly blue-shifted from the absorption and emission bands of dye molecules, exhibited most efficient fluorescenc enhancements. Relative contributions of enlarged electric fields around the nanoparticles and SPCE to the total fluorescence enhancements of DCM and Rh700 were investigated by time-resolved fluorescence spectroscopy (TCSPC and femtosecond transient absorption techniques) and FDTD simulations. The emission of both dyes was found as dominantly increased by the induced local electric fields rather than the plasmon coupled emissions.
E-mail leedd1896@gist.ac.kr