次氯酸及硫醇螢光化學感測分子之設計與合成及於活體細胞的應用

Abstract

本論文設計以NBD與coumarin為螢光基團，偵測次氯酸與硫醇分子的感測分子NBDS和CAA。NBDS以硫酚基團作為與次氯酸的反應辨識端，硫酚基團產生的PET機制使NBDS放出很弱螢光（Φ = 0.001），而與次氯酸作用後，硫酚基團反應產生苯亞碸基團，使PET效應被阻礙進行，進而產生111倍的綠色螢光強度增加（Φ = 0.111）。NBDS在各種ROS與RNS中具有良好的選擇性與靈敏性偵測次氯酸，偵測極限約為73 nM (S/N = 3)。此外，利用共軛焦顯微鏡觀察感測分子NBDS可應用於巨噬細胞偵測次氯酸。 第二部分是偵測硫醇分子的感測分子CAA，以丙烯醯胺基團作為硫醇的辨識端。CAA在胺基酸中具有很好的選擇性與靈敏性偵測硫醇，並進一步研究CAA與Cys反應後之螢光產物，發現Cys上的硫醇會經由Michael加成於雙鍵上，形成新的螢光化合物。最後，在螢光顯影實驗中，感測分子CAA可應用於巨噬細胞偵測硫醇分子。

In this thesis, NBD-based and coumarin-based chemosensors NBDS and CAA were designed for detection of HOCl and thiol. NBDS containing an organosulfur group as a reaction moiety for HOCl. NBDS shows weak fluorescence with a quantum yield (Φ = 0.001) due to photo-induced electron from the phenyl sulfide to NBD fluorophore. 111-Fold green fluorescence enhancement (Φ = 0.111) was produced upon oxidation of sulfur by HOCl, due to the block of PET process. NBDS exhibits good selectivity and sensitivity for HOCl over other ROS and RNS. It shows a low detection limit of 73 nM (S/N = 3). Confocal fluorescence microscopy imaging using RAW264.7 cells shows that NBDS could be an efficient fluorescent probe for HOCl in living cells. In second part, CAA uses an acrylamide group as a recognition moiety for thiol detection. CAA shows good selectivity and sensitivity for thiol detection over other amino acids. After the reaction of CAA with Cys, a new fluorescent product from the Michael-type reaction with Cys on the double bond is observed. Confocal fluorescence microscopy imaging using RAW264.7 cells shows that CAA could be an efficient probe.