近年來螢光感測器應用於對金屬離子的感測越來越受到關注，金屬離子維持人體許多功能的運行，金屬離子在人體中的量過多或過少均會造成危害，因此檢測金屬離子在環境中的含量變得極其重要。相較於其他測定金屬離子的儀器，螢光感測器有許多優點，例如：容易操作、成本低、量測時間短。
本研究合成出含希夫鹼之噁二唑衍生物O1作為金屬離子螢光感測器
， O1因光誘導電子轉移(photo-induced electron transfer, PET)的作用，螢光強度低。於乙醇/水(7:1, v/v)中探討對金屬離子的辨識能力及形成錯合物的機制，鋅離子選擇性地增強螢光強度(λem = 465 nm，33倍)，造成此現象的原因是O1與鋅離子作用使光誘導電子轉移被抑制，進而造成螢光增強。同時螢光光譜產生藍位移，推測是鋅離子與電子給予imine基(-C=N-)氮原子的強作用，提高了激發態與基態間的能量差。由Job plot實驗得到O1與鋅離子形成錯合物的配位比例是1:2，由濃度滴定實驗得到偵測極限(LOD)是3.08×10-8M。O1在pH = 6到pH = 11的環境下皆可有效地感測鋅離子。在可逆性方面，加入強螯合化合物Na2EDTA抓走結合的Zn2+，導致螢光隨時間淬熄，隨後再加入Zn2+可觀察到螢光恢復增強現象，顯示O1是具良好可逆性的感測材料。利用TICT(English)理論解釋溶劑效應，溶劑極性越大，放光波長紅移現象越明顯，在UV燈照射下可用肉眼觀察到顏色從藍色變化成青綠色。溫度的影響則是O1-Zn2+在室溫時的放光強度，明顯高於高溫時。

A novel fluorescent sensor O1, containing oxadiazolyl core and two terminal imine (azomethime) moieties, was synthesized by the Suzuki coupling reaction and imine condensation. O1 exhibits weak fluorescence owing to photo-induced electron transfer (PET) and C=N isomerization. In the presence of Zn2+, the fluorescence “turns on” and its intensity increases significantly with increasing concentration of Zn2+. The chemical structure of O1 was satifactorily characterized by 1H NMR and MALDI/TOF-MS spectra. 1H NMR and FTIR spectral results confirm the formation of O1-Zn2+complex. Moreover, the Job plot reveals formation of the O1–Zn2+ complex with 1:2 stoichiometry. In the presence of strong chelating Na2EDTA the O1-Zn2+ fluorescence quenches significantly. The binding constant and limit of detection (LOD) are 6.7×108 M-2and 3.08×10-8M, respectively, estimated from titration data.

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