[AuI4]^--RDG^+缔合物纳米微粒体系的共振散射增强与荧光猝灭

On the Fluorescence Quenching and Resonance Scattering Behavior of ((AuI_4)RDG)_n Association Nanoparticle System

在 0 .2 mol/L HCl介质中 ,罗丹明 6 G( RDG)分别在 5 2 0和 5 5 0 nm处有 1个吸收峰和荧光峰。当有Au( )和 KI存在时 ,Au( )与 I-形成 Au I- 4 ,Au I- 4 与 RDG+主要通过静电引力形成疏水性的 ( Au I4) RDG缔合物分子。 ( Au I4) RDG分子间存在较强的分子间作用力和疏水作用力而生成 ( ( Au I4) RDG) n 纳米微粒 ,在6 0 0 nm产生 1个特征共振散射峰 ,并且 5 5 0 nm荧光峰和 5 2 0 nm吸收峰降低。当纳米微粒体系加入乙醇后 ,体系的红紫色和共振散射峰消失 ,吸收峰和荧光峰恢复 ,由于乙醇致使 ( ( Au I4) RDG) n 纳米微粒分解为( Au I4) RDG分子。研究结果表明 ,红紫色 ( ( Au I4) RDG) n 纳米粒子的形成是其共振散射增强、荧光猝灭、产生特征共振散射峰和减色效应的根本原因。

A maximum absorption peak at 520 nm and a fluorescence peak at 550 nm were observed for rhodamine 6G(RDG) in 0.2 mol/L HCl. In the presence of KI and Au(Ⅲ), the AuI - 4 and RDG + combine into hydrophobic AuI 4-RDG association molecule through electric attraction. The strong Van der Waals force and hydrophobic forces among AuI 4-RDG molecules lead to the formation of ((AuI 4)-RDG) n association nanoparticles in red-violet color which exhibit a characteristic resonance scattering peaks at 600 nm and fluorescence quenching at 550 nm. The ((AuI 4)RDG) n nanoparticles could be decomposed into individual (AuI 4)RDG association molecule by alcohol and the resonance scattering peaks and the red-violet color disappeared, whereas the A 520 nm and F 470 nm /550 nm occurred again. The results demonstrate that the formation of ((AuI 4)RDG) n composite nanoparticle in red-violet and the interface between the nanoparticle solid phase and water phase give rise to its enhanced resonance scattering,fluorescence quenching, hypochromic effect with a characteristic resonance scattering peaks at 600 nm.