College of Materials Science & Engineering, South China University of Technology, Guangzhou 510640, China.
Chemphyschem. 2010 Apr 6;11(5):1036-43. doi: 10.1002/cphc.200900999.
The nanoparticle-based fluorescence resonance energy transfer (FRET) systems have recently attracted considerable attention due to some of their advantages; however, these systems are structurally more complicated than that of small molecule systems, and the energy transfer behavior for particle systems has been seldom investigated. In this study, we synthesized a series of ABC triblock copolymers that contain hydrophilic poly(ethylene oxide) (PEO), hydrophobic poly(styrene) (PS) and photochromic poly(2-(3-(3',3'-dimethyl-6-nitrospiro(indoline-2',2-[2H-1]benzopyran)-1'-yl)propanoylo-xy)ethyl methacrylate) (PSPMA) blocks by using the sequential two-step atom transfer radical polymerization (ATRP). The amphiphilic micelles made from these copolymers can incorporate a hydrophobic fluorescent dye, the nitrobenzoxadiazolyl derivative (NBD), thus forming a water dispersible energy transfer system with the fluorescent dye NBD as the donor and spiropyran moieties as the potential acceptor. The spectral properties of NBD/triblock copolymers with varied PS block lengths and PSPMA block lengths have been investigated; the results indicate that the length of PS block in triblock copolymers can affect the energy transfer efficiency of the micelle-based fluorescence modulation system, the micelles with moderate PS block length are preferable for forming FRET system with higher energy transfer efficiency, and short PSPMA blocks (less than 5 repetition units) are enough for efficient energy transfer.
基于纳米粒子的荧光共振能量转移（FRET）系统由于其某些优势而引起了相当大的关注；然而，这些系统比小分子系统的结构更为复杂，并且对粒子系统的能量转移行为研究甚少。在这项研究中，我们通过两步顺序原子转移自由基聚合（ATRP）合成了一系列含有亲水性聚（氧化乙烯）（PEO）、疏水性聚（苯乙烯）（PS）和光致变色聚（2-（3-（3'，3'-二甲基-6-硝基螺[吲哚啉-2'，2-[2H-1]苯并吡喃]-1'-基）丙酰氧基）乙基甲基丙烯酸酯）（PSPMA）嵌段的 ABC 三嵌段共聚物。这些共聚物形成的两亲性胶束可以掺入疏水性荧光染料硝基苯并恶唑基衍生物（NBD），从而形成具有荧光染料 NBD 作为供体和螺吡喃部分作为潜在受体的水分散能量转移系统。我们还研究了具有不同 PS 嵌段长度和 PSPMA 嵌段长度的 NBD/三嵌段共聚物的光谱性质；结果表明，三嵌段共聚物中 PS 嵌段的长度可以影响基于胶束的荧光调制系统的能量转移效率，具有适中 PS 嵌段长度的胶束更适合形成具有更高能量转移效率的 FRET 系统，并且短 PSPMA 嵌段（少于 5 个重复单元）足以进行有效的能量转移。
