有机分子隔离层对机械抛光金属银表面的罗丹明6G荧光增强效应的影响

采用物理吸附法,在机械抛光纯银表面引入对巯基苯胺(p-Amiothiophenol,PATP)分子充当隔离层,运用激光光谱学方法研究隔离层对位于银表面附近的罗丹明6G(Rh6G)分子的荧光增强效应影响。实验结果表明,未经PATP分子修饰的机械抛光金属衬底对Rh6G分子表现为猝灭效应,而经过PATP分子修饰后的银表面对Rh6G分子的荧光发射具有增强效应。根据局域表面等离子共振及辐射能量转移模型对实验观测所得结果进行了分析研究,结果表明,PATP有机分子隔离层的引入有效地减小了荧光分子与金属衬底之间的无辐射能量速率,提高了荧光辐射强度。

Surface Enhanced Fluorescence from Physically Polished Silver Substrate Decorated with and without Organic Molecule Layer

The fluorescence emission of Rhodamine 6G dye molecules located near the physically polished nanostructure silver substrate(PPNSS) with and without PATP monolayer was investigated.The quenching effect is observed when the dye molecule is directly adsorbed onto PPNSS without the formation of PATP monolayer.However,the fluorescence is enhanced when the PATP layer is formed.This phenomenon is discussed by taking into account the formation of PATP monolayer,the nonradiative energy transfer process and the local surface plasmon resonance at rough silver surface.A theoretical model is proposed for analyzing the role of the PATP layer formed on the metal substrate.It indicates that isolated spacer formed on metal nanostructure substrate can enhance fluorescence.