Lee Daedu, Lee Jaebeom, Song Junghyun, Jen Myungsam, Pang Yoonsoo
Department of Chemistry, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju 61005, Republic of Korea.
Phys Chem Chem Phys. 2019 Jun 5;21(22):11599-11607. doi: 10.1039/c9cp00585d.
Homogeneous silver colloidal films (SCFs), composed of silver nanoparticles 67-193 nm in diameter, were synthesized by a seeded-growth method as the substrates for metal-enhanced fluorescence (MEF). The homogeneity and uniform particle distribution of the SCFs showed many advantages for the exploration of the MEF mechanism. The fluorescence enhancement of 4-(dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM) and rhodamine 700 (Rh700) dyes dispersed in a thin layer of polystyrene (PS) with the SCFs was observed by time-resolved fluorescence spectroscopy. The fluorescence enhancements of DCM and Rh700 become larger when the surface plasmon resonance bands of SCFs overlap the emission bands of dyes. The particle-size-dependent changes of the radiative and non-radiative rate constants of both dyes with the SCFs are estimated by an improved analysis combining the fluorescence intensity and lifetime measurements and the finite-difference time-domain method simulations.
通过种子生长法合成了由直径为67 - 193 nm的银纳米颗粒组成的均匀银胶体薄膜（SCF），作为金属增强荧光（MEF）的基底。SCF的均匀性和均匀的颗粒分布在探索MEF机制方面显示出许多优势。通过时间分辨荧光光谱法观察到，分散在具有SCF的聚苯乙烯（PS）薄层中的4 - （二氰基亚甲基） - 2 - 甲基 - 6 - （4 - 二甲基氨基苯乙烯基） - 4H - 吡喃（DCM）和罗丹明700（Rh700）染料的荧光增强。当SCF的表面等离子体共振带与染料的发射带重叠时，DCM和Rh700的荧光增强变得更大。通过结合荧光强度和寿命测量以及时域有限差分法模拟的改进分析，估计了两种染料与SCF的辐射和非辐射速率常数的粒径依赖性变化。
