Toyota Central R&D Laboratories, Inc. Nagakute, Aich 480-1192, Japan.
Chemistry. 2012 Feb 13;18(7):1992-8. doi: 10.1002/chem.201102492. Epub 2012 Jan 13.
Enhanced fluorescence detection of metal ions was realized in a system consisting of a fluorescent 2,2'-bipyridine (BPy) receptor and light-harvesting periodic mesoporous organosilica (PMO). The fluorescent BPy receptor with two silyl groups was synthesized and covalently attached to the pore walls of biphenyl (Bp)-bridged PMO powder. The fluorescence intensity from the BPy receptor was significantly enhanced by the light-harvesting property of Bp-PMO, that is, the energy funneling into the BPy receptor from a large number of Bp groups in the PMO framework which absorbed UV light effectively. The enhanced emission of the BPy receptor was quenched upon the addition of a low concentration of Cu(2+) (0.15-1.2×10(-6) M), resulting in the sensitive detection of Cu(2+). Upon titration of Zn(2+) (0.3-6.0×10(-6) M), the fluorescence excitation spectrum was systematically changed with an isosbestic point at 375 nm through 1:1 complexation of BPy and Zn(2+) similar to that observed in BPy-based solutions, indicating almost complete preservation of the binding property of the BPy receptor despite covalent fixing on the solid surface. These results demonstrate that light-harvesting PMOs have great potential as supporting materials for enhanced fluorescence chemosensors.
在由荧光 2,2'-联吡啶（BPy）受体和光收集周期性介孔有机硅（PMO）组成的体系中实现了金属离子的增强荧光检测。具有两个硅烷基的荧光 BPy 受体被合成并共价键合到联苯（Bp）桥联 PMO 粉末的孔壁上。BPy 受体的荧光强度通过 Bp-PMO 的光收集特性显著增强，即能量从 PMO 骨架中大量的 Bp 基团中有效地传递到 BPy 受体，这些基团有效地吸收了紫外光。当加入低浓度的 Cu(2+)（0.15-1.2×10(-6) M）时，BPy 受体的增强发射被猝灭，从而实现了对 Cu(2+)的灵敏检测。当滴定 Zn(2+)（0.3-6.0×10(-6) M）时，荧光激发光谱通过 1:1 配合物 BPy 和 Zn(2+)发生系统性变化，在 375nm 处出现等色点，类似于在 BPy 基溶液中观察到的情况，这表明尽管 BPy 受体固定在固体表面上，但结合性质几乎完全得到保留。这些结果表明，光收集 PMO 作为增强荧光化学传感器的支撑材料具有很大的潜力。
