Boron dipyrromethene fluorophore based fluorescence sensor for the selective imaging of Zn(II) in living cells

• Published in: Organic & biomolecular chemistry 2005-04, Vol.3 (8), p.1387-1392
• Main Authors: Wu, Yunkou, Peng, Xiaojun, Guo, Binchen, Fan, Jiangli, Zhang, Zhichao, Wang, Jingyun, Cui, Aijun, Gao, Yunling
• Format: Article
• Language: English
• Subjects: Animals; Boron Compounds - chemistry; Cations - chemistry; Fluorescent Dyes - chemical synthesis; Fluorescent Dyes - chemistry; Heterocyclic Compounds, 3-Ring - chemistry; Magnetic Resonance Spectroscopy; Models, Molecular; Molecular Conformation; PC12 Cells; Protons; Rats; Spectrometry, Fluorescence; Zinc - chemistry; Zinc - metabolism
• ISSN: 1477-0520; 1477-0539
• DOI: 10.1039/b501795e

A simple PET fluorescence sensor (BDA) for Zn2+ that utilizes 1,3,5,7-tetramethyl-boron dipyrromethene as a reporting group and di(2-picolyl)amine as a chelator for Zn2+ has been synthesized and characterized. BDA has an excitation (491 nm) and emission wavelength (509 nm) in the visible range. The fluorescence quantum yields of the zinc-free and zinc-bound states of BDA are 0.077 and 0.857, respectively. With a low pKa of 2.1 +/- 0.1, BDA has the advantage of less sensitivity to pH than fluorescein-based Zn2+ sensors, and the fluorescence emission of zinc-binding is pH-independent in the range of pH 3-10. Under physiological conditions, metal ions such as Na+, K+, Ca2+, Mg2+, Mn2+ and Fe2+ have little interference. The apparent dissociation constant (Kd) is 1.0 +/- 0.1 nM. Using fluorescence microscopy, the sensor is shown to be capable of imaging intracellular Zn2+ changes.