Department of Chemistry, Durham University, South Road, Durham, DH1 3LE, UK.
Research and Development Cisbio Bioassays, BP 84175, 30200, Codolet, France.
Chemistry. 2021 Jan 7;27(2):766-777. doi: 10.1002/chem.202003992. Epub 2020 Dec 15.
A set of four luminescent Eu complexes bearing an extended aryl-alkynylpyridine chromophore has been studied, showing very different pH-dependent behaviour in their absorption and emission spectral response. For two complexes with pK values of 6.45 and 6.20 in protein-containing solution, the emission lifetime increases very significantly following protonation. By varying the gate time during signal acquisition, the 'switch-on' intensity ratio could be optimised, and enhancement factors of between 250 to 1330 were measured between pH 8 and 4. The best-behaved probe showed no significant emission dependence on the concentration of endogenous cations, reductants, and serum albumin. It was examined in live-cell imaging studies to monitor time-dependent lysosomal acidification, for which the increase in observed image brightness due to acidification was a factor of 50 in NIH-3T3 cells.
研究了一组带有扩展的芳基-炔基吡啶生色团的四个发光 Eu 配合物，它们在吸收和发射光谱响应方面表现出非常不同的 pH 依赖性。对于两个在含蛋白质溶液中的 pK 值为 6.45 和 6.20 的配合物，质子化后发射寿命显著增加。通过在信号采集过程中改变门控时间，可以优化“开启”强度比，并且在 pH 8 和 4 之间测量到 250 到 1330 之间的增强因子。表现最好的探针在检测内源性阳离子、还原剂和血清白蛋白浓度时，其发射没有明显的依赖性。它在活细胞成像研究中被用来监测溶酶体酸化的时间依赖性，由于酸化导致观察到的图像亮度增加了 50 倍，这是 NIH-3T3 细胞中的一个因素。
