Synthesis and time-resolved fluorimetric application of a europium chelate-based phosphorescence probe specific for singlet oxygen
作者:Bo Song、Guilan Wang、Mingqian Tan、Jingli Yuan
DOI:10.1039/b510611g
日期:——
A new europium chelate, [4′-(9-anthryl)-2,2′:6′,2′′-terpyridine-6,6′′-diyl]bis(methylenenitrilo) tetrakis(acetate)-Eu3+
(ATTA-Eu3+), has been designed and synthesized as a highly sensitive and selective time-resolved phosphorescence probe for singlet oxygen (1O2). The probe can specifically react with 1O2 to yield its endoperoxide (EP-ATTA-Eu3+) with a great increase of the luminescence quantum yield and a long phosphorescence lifetime of 1.21 ms, which renders the probe favorable to be used for highly sensitive time-resolved luminescence detection of 1O2. The new phosphorescence probe is highly water soluble with a large stability constant of ∼1020 and a wide available pH range at pH > 3. Upon reactions with some reactive oxygen species including hydrogen peroxide, superoxide, hydroxyl radical and 1O2, the probe shows high specificity for 1O2. The probe was used for quantitative detection of 1O2 generated from a MoO42−–H2O2 system to give a detection limit of 2.8 nM. Furthermore, the good applicability of the probe was demonstrated by the real-time monitoring of the kinetic process of 1O2 generation in a horseradish peroxidase (HRP) catalyzed oxidation system of indole-3-acetic acid (IAA) in a weakly acidic buffer and in a photosensitization system of 5,10,15,20-tetrakis(N-methyl-4-pyridyl)-21H,23H-porphine (TMPyP) in a neutral buffer.
设计并合成了一种新型铕螯合物[4′-(9-蒽基)-2,2′:6′,2′′-三联吡啶-6,6′′-二基]双(亚甲基亚胺基)四(乙酸酯)-Eu3+ (ATTA-Eu3+),作为单线态氧(1O2)的高灵敏度和高选择性的时间分辨荧光探针。该探针能特异性地与1O2反应,生成其内过氧化物(EP-ATTA-Eu3+),其发光量子产率大幅增加,荧光寿命长达1.21 ms,使得该探针有利于用于高灵敏度时间分辨荧光检测1O2。新型荧光探针具有高水溶性,稳定常数大,且在pH > 3时适用pH范围广。该探针在与包括过氧化氢、超氧阴离子、羟基自由基和1O2在内的活性氧物种反应时,对1O2表现出高度的选择性。该探针用于MoO42−–H2O2体系产生的1O2的定量检测,检测限为2.8 nM。此外,通过在弱酸性缓冲液中实时监测HRP催化的吲哚-3-乙酸(IAA)氧化体系中1O2的生成动力学过程,以及在中性缓冲液中实时监测5,10,15,20-四(N-甲基-4-吡啶基)-21H,23H-卟啉(TMPyP)光敏化体系中1O2的生成动力学过程,证明了该探针的良好适用性。