Department of Microbial and Molecular Systems, Centre for Surface Chemistry and Catalysis, Katholieke Universiteit Leuven, Kasteelpark Arenberg 23, B-3001 Leuven, Belgium.
J Am Chem Soc. 2009 Mar 4;131(8):3049-56. doi: 10.1021/ja810071s.
Thermal treatment of Ag(+)-exchanged zeolites yields discrete highly photostable luminescent clusters without formation of metallic nanoparticles. Different types of emitters with characteristic luminescence colors are observed, depending on the nature of the cocation, the amount of exchanged silver, and the host topology. The dominant emission bands in LTA samples are situated around 550 and 690 nm for the samples with, respectively, low and high silver content, while in FAU-type materials only a broad band around 550 nm is observed, regardless of the degree of exchange. Analysis of the fluorescent properties in combination with ESR spectroscopy suggests that a Ag(6)(+) cluster with doublet electronic ground state is associated with the appearance of the 690-nm emitter, having a decay of a few hundred microseconds. Tentatively, the nanosecond-decaying 550-nm emitter is assigned to the Ag(3)(+) cluster. This new class of photostable luminescent particles with tunable emission colors offers interesting perspectives for various applications such as biocompatible labels for intracellular imaging.
Ag(+) 交换沸石的热处理产生离散的高光照稳定性的发光团簇，而不会形成金属纳米粒子。根据阳离子的性质、交换银的量和宿主拓扑结构，可以观察到具有特征发光颜色的不同类型的发射器。LTA 样品的主要发射带位于 550nm 和 690nm 左右，分别对应于低银含量和高银含量的样品，而在 FAU 型材料中，无论交换程度如何，仅观察到约 550nm 的宽带。荧光性质分析与 ESR 光谱学相结合表明，具有双重电子基态的 Ag(6)(+)簇与 690nm 发射器的出现有关，其衰减时间为数百微秒。暂定地，纳秒衰减的 550nm 发射器被分配给 Ag(3)(+)簇。这种具有可调发射颜色的新型光稳定发光颗粒为各种应用提供了有趣的前景，例如用于细胞内成像的生物相容性标记物。
