近年來有許多關於綠色螢光蛋白發光團的研究，由於其被蛋白包覆進而使得發光團穩定，所以導致它能夠釋放強烈綠色螢光，但是當其離開蛋白的包覆時會使其螢光大幅下降。近年來更是有許多與綠色螢光蛋白發光團類似物合成之探討，不管是機制還是及其應用，利用螢光的特性當作生物感測器、生物標記抑或是化學感測器。因C=S官能基在硫脲基團中對於金屬離子親合的特性，所以將此基團引入我們所合成的鄰位綠色螢光蛋白發光團類似物(o-ABDI)，進一步合成化合物o-ECTUBDI，應用於金屬離子偵測。經過實驗研究發現，o-ECTUBDI可以感測到Cr3+、Fe3+、Hg2+及Cu2+，比較與金屬離子結合前後的光物理特性，發現於定量之o-ECTUBDI逐漸滴定四種金屬離子後會在吸收光譜有isosbestic point出現，且螢光光譜皆呈現螢光淬滅，由Benesi-Hildebrand plot計算得與Fe3+之結合常數最大、Hg2+的最小。因此我們可以利用化合物o-ECTUBDI來偵測這些特定的金屬離子。
此外，在於化學感測器o-ECTUBDI之可逆性研究方面，我們發現這些金屬錯合物在滴定EDTA時，EDTA能進一步地將Cr3+和Hg2+從錯合物中抓出來，然而Fe3+及Cu2+並不會有相同的情況發生。因此，對於Cr3+和Hg2+金屬離子而言，o-ECTUBDI為一可逆的化學感測器；Fe3+及Cu2+之金屬錯合物則為非可逆性的偵測。我們在進行感測器可逆性探討時發現，化合物o-ECTUBDI會與EDTA藉由氫鍵作用，形成一超分子結合的現象，進而導致另一螢光放射峰產生並且隨著EDTA滴定，螢光放射強度隨之增加。我們將EDTA分子結構拆分為另外三者，並從中發現ethylenediamine diacetic acid與EDTA具有相同的效果，藉此推論與o-ECTUBDI產生氫鍵形成堆疊的結構即類似於ethylenediamine diacetic acid，因而觀察到超分子結合的現象。
從化合物o-ECTUBDI的X-ray單晶結構中觀察得知，其具備不同以往的鄰位綠色螢光蛋白發光團類似物之順式結構，硫脲基團轉至化合物的另一側，藉由Mercury和Diamond軟體發現，o-ECTUBDI分子會利用分子間氫鍵來進行堆疊，以形成一個更為穩定的結構，所以當中的硫脲基團才會轉至化合物的另一側。此外，我們使用不同極性的溶劑來觀察o-ECTUBDI在吸收及螢光光譜的光物理特性，從中發現它在高極性溶劑中會產生另一較長波長的螢光放射峰於550-600 nm的位置，其原因為高極性溶劑改變了化合物o-ECTUBDI的構型使其轉回順式結構，進而產生激發態分子內的氫轉移現象，因此我們才能於長波長的螢光光譜中得其兩性離子異構物的螢光放射峰。

We design an ortho analogue of GFP chromophore(o-ECTUBDI) which can sense particular metal ions, such as Cu2+, Fe3+, Cr3+and Hg2+, and lead to fluorescence static quenching in fluorescent emission spectrums. Hence, these results could offer an evidence that o-ECTUBDI can be a chemosensor for detection of these four metal ions. And we found that o-ECTUBDI is a reversible chemosensor when it binds with Cr3+and Hg2+ ions. Conversely, the complex of o-ECTUBDI and Cu2+ and Fe3+ makes it be an irreversible sensor. Besides, we observe proof that o-ECTUBDI makes use of hydrogen bonding to have interaction with specific organic molecules, like EDTA and ethylenediamine diacetic acid, with a fluorescence emission intensity increasing in this supramolecular assembling region.
And the other interesting property of ortho analogues of GFP chromophore is generally shown that they will be a cis form conformation. But, o-ECTUBDI revealed that its X-ray single crystal conformation is not same as other ortho analogues. The thiourea group of o-ECTUBDI rotates to the other side because of the intermolecular hydrogen bonding between two o-ECTUBDI molecules. And this non-covalent force makes it to become a more stable structure in solid state. Further, we use various solvents from polarity to non-polarity to observe the o-ECTUBDI difference in these solvents. In the polarity solvents, such as H2O, MeOH and DMSO, it will create an excited state intramolecular proton transfer(ESIPT) phenomenon and produce a large stoke shift of fluorescence emission. Consequently, we can use solvents polarity to control o-ECTUBDI structure conformation and study its ESIPT mechanism.

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