Firefly bioluminescence quantum yield and colour change by pH-sensitive green emission
Firefly bioluminescence quantum yield and colour change by pH-sensitive green emission
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DOI：
10.1038/nphoton.2007.251
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发表时间：
2008-01-01
期刊：
影响因子：
35
通讯作者：
Akiyama, Hidefumi
中科院分区：
文献类型：
--
作者：
Ando, Yoriko;Niwa, Kazuki;Akiyama, Hidefumi
萤火虫生物发光(1-19)是生物光子学中最著名的理想光致发光体系，特别是其极高的量子产率(88+/-25%)(参考文献2，3)或更高(4-6)，以及它在黄绿色和红色之间与pH有关的发射颜色变化(3，7)，模拟为两个对应状态(8-14)之间的化学平衡。然而，还讨论了重新审查的必要性(4-6)。在这封信中，我们使用我们新的全光子通量光谱仪(20，21)来量化量子产率和颜色变化。我们测得最高量子产率为41.0+/-7.4%(1标准差(S.D.)估计，覆盖因子k=1)，发现生物发光光谱被系统地分解为一个对pH敏感的和两个对pH不敏感的高斯分量。黄绿色和红色发射之间没有通过pH平衡的强度转换，但在2.2 eV处对pH敏感的高斯峰的简单强度变化导致了发射颜色的变化。这代表着颜色决定概念的范式转变，不再是基于pH平衡的长期解释。
Firefly bioluminescence(1-19) is the most well-known ideal photoemitter system in biophotonics, known in particular for its extremely high quantum yield, 88 +/- 25% (refs 2,3) or higher(4-6), and its magnificent pH-dependent emission-colour change(3,7) between yellow-green and red, modelled as the chemical equilibrium between two corresponding states(8-14). However, the need for re-examination has also been discussed(4-6). In this letter we quantify quantum yields and colour changes using our new total-photon-flux spectrometer(20,21). We determine the highest quantum yield to be 41.0 +/- 7.4% (1 standard deviation (s.d.) estimate, coverage factor k = 1), and find that bioluminescence spectra are systematically decomposed into one pH-sensitive and two pH-insensitive gaussian components. There is no intensity conversion between yellow-green and red emissions through pH equilibrium, but simple intensity variation of the pH-sensitive gaussian peak at 2.2 eV causes the changes in emission colours. This represents a paradigm shift in the concept of colour determination from long-standing interpretation based on pH equilibrium.