近年來有許多關於綠色螢光蛋白發光團的研究，像綠色螢光蛋白發光團的人工合成方式，或是解釋綠色螢光蛋白發光團離開生物體後螢光下降的原因，亦或是用於生物標定、化學感測器。因此我們試著以綠色螢光蛋白發光團為發色團接上對金屬離子具有親和性的尿素基團，成功合成對Fe3+和Cu2+具有辨識能力的o-ECUBDI。金屬感測器辨識的表現有螢光增強現象、螢光淬熄現象或著螢光一消一長的比列式螢光，其中比列式螢光可以通過兩個放射帶的自我校準來限制環境干擾、儀器干擾等許多外在因素。而o-ECUBDI就是屬比列式螢光感測器，並且原本的螢光與新產生的螢光有巨大的紅移，使比列式螢光的優點能夠發揮。除此之外，從o-ECUBDI的X-ray單晶結構也觀察到了與過去鄰位螢光蛋白衍生物不同的立體結構，並通過了Mercury軟體的分析，不同與過去鄰位螢光蛋白衍生物具有分子內氫鍵造成s-cis form，o-ECUBDI具有分子間氫鍵造成s-trans form的堆疊。

We design an ortho analogue of GFP chromophore(o-ECUBDI) which can selectively sense metal ions, such as Cu2+ and Fe3+, and reveal ratiometric fluorescent. As the change in fluorescence intensity is the only detection signal, factors such as instrumental efficiency and environmental conditions can interfere with the signal output. Ratiometric sensors can eliminate most ambiguities by self-calibration of two emission bands. On top of that, o-ECUBDI has a distant dual-fluorescent which can prevent high intensity completely covers one with lower intensity. The other notable property of o-ECUBDI is that it shows an unusual conformation. Unlike general ortho analogues of GFP Chromophore are s-cis conformations but o-ECUBDI expresses s-trans in X-ray single crystal. Through Mercury calculates the X-ray data, we find s-trans conformation results from an intermolecular hydrogen bonding.

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