College of Materials Science and Engineering, South China University of Technology, Guangzhou 510640, People's Republic of China.
Nanotechnology. 2010 May 14;21(19):195501. doi: 10.1088/0957-4484/21/19/195501. Epub 2010 Apr 21.
A facile strategy was employed to create a fluorescence resonance energy transfer (FRET) based ratiometric sensing system for ferric ions in all-aqueous media by using nanosized poly(ethylene oxide)-b-polystyrene micelles as the scaffold. A hydrophobic fluorescent dye nitrobenzoxadiazolyl derivative (NBD), which served as the energy transfer donor, was incorporated into the micelle core during the micelle formation; a spirolactam rhodamine derivative (SRhB-OH) was chosen as a sensitive and selective sensor for Fe(III) ions and was then 'adsorbed' into the micelle core/corona interface. A highly efficient ring-opening reaction of SRhB-OH induced by Fe(III) generates the long-wavelength rhodamine B fluorophore which can act as the energy acceptor; thus, the micelle nanoparticles can serve as a FRET-based ratiometric detection system for ferric ions. The effects of PS block length on the ion sensing performance of the micelles were investigated, and it has been found that the micelles formed by the copolymer with moderate block length (PEO(113)-b-PS(115)) were preferable as the scaffold for the FRET system and exhibited a sensitive and selective sensing capacity for Fe(III) with a detection limit of 1 microM. This nanoparticle-based sensing strategy may be utilized to construct other ratiometric chemosensors by replacing the current dyes with other suitable ones.
一种简便的策略被用来在全水介质中创建基于荧光共振能量转移（FRET）的比率型铁离子传感系统，该策略使用纳米级聚（氧化乙烯）-b-聚苯乙烯胶束作为支架。一种疏水性荧光染料硝酮基衍生物（NBD）被用作能量转移供体，在胶束形成过程中被掺入胶束核心；螺环缩酮罗丹明衍生物（SRhB-OH）被选择为 Fe（III）离子的敏感和选择性传感器，然后被“吸附”到胶束核/冠界面。Fe（III）诱导的 SRhB-OH 的高效开环反应生成长波长罗丹明 B 荧光团，可作为能量受体；因此，胶束纳米颗粒可用作基于 FRET 的铁离子比率检测系统。研究了 PS 嵌段长度对胶束离子传感性能的影响，发现具有中等嵌段长度的共聚物（PEO（113）-b-PS（115））形成的胶束作为 FRET 系统的支架更为理想，并对 Fe（III）具有敏感和选择性的传感能力，检测限为 1 μM。这种基于纳米颗粒的传感策略可以通过用其他合适的染料替代当前的染料来构建其他比率型化学传感器。
