Tremblay Matthew S, Halim Marlin, Sames Dalibor
Department of Chemistry, Columbia University, New York, New York 10027, USA.
J Am Chem Soc. 2007 Jun 20;129(24):7570-7. doi: 10.1021/ja070867y. Epub 2007 May 23.
Fluorescent and luminescent reporters that signal molecular events of interest by modulating the ratio of peaks in their emission profile have advantages over reporters that simply modulate their emission intensity, since ratiometric measurement is concentration-independent and allows them to be effective in complex contexts, such as living cells or sensor microarrays. We herein describe a general platform for the design of ratiometric probes based on a heterometallic Tb(3+)/Eu(3+) bis-lanthanide ensemble, consisting of a mixture, or "cocktail", of otherwise identical heterometalated chelates. The chelate contains an organic photon antenna that sensitizes the Tb(3+)/Eu(3+) luminescence. The contributions of the two metals to the composite luminescence spectrum can be tuned to the same relative scale by adjusting the stoichiometry of the cocktail, allowing subtle changes in their ratio to be accurately measured. Importantly, the ratio responds to chemical and environmental changes experienced by the photon antenna, making the system an ideal platform for the design of chemical and enzymatic probes. As proofs of concept, we describe a ratiometric probe for esterase activity and a polarity-responsive ratiometric sensor.
通过调节发射谱中峰的比例来指示感兴趣分子事件的荧光和发光报告分子，相较于仅调节发射强度的报告分子具有优势，因为比率测量与浓度无关，使其在复杂环境（如活细胞或传感器微阵列）中也能有效发挥作用。我们在此描述了一个基于异金属Tb(3+)/Eu(3+)双镧系元素组合设计比率探针的通用平台，该组合由一组相同的异金属螯合物的混合物或“鸡尾酒”组成。螯合物包含一个有机光子天线，可敏化Tb(3+)/Eu(3+)的发光。通过调整“鸡尾酒”的化学计量比，可将两种金属对复合发光光谱的贡献调节到相同的相对尺度，从而能够精确测量它们比例的细微变化。重要的是，该比例会对光子天线所经历的化学和环境变化做出响应，使该系统成为设计化学和酶探针的理想平台。作为概念验证，我们描述了一种用于酯酶活性的比率探针和一种对极性响应的比率传感器。
