以NBD-SCN作為比色和螢光雙功能的探針

Abstract

本研究設計並合成了一個親水性探針，NBD-SCN，可以檢測出四個特定的生物硫醇(硫化氫、半胱胺酸、高半胱胺酸和穀胱甘肽)。特別的是，NBD-SCN可透過肉眼觀察顏色的變化和紫外光-可見光光譜儀的分析區分生物硫醇：硫化氫能引起NBD-SCN的顏色變化從無色變為紫色，吸收光譜會在530 nm處產生新的吸收峰，將530 nm吸收峰強度與硫化氫濃度作圖，顯示NBD-SCN與硫化氫具有高度的線性關係，經由理論計算後可得偵測極限為0.21 µM；半胱胺酸和高半胱胺酸能引起NBD-SCN的顏色變化從無色變為橙色，吸收光譜會在480 nm處產生新的吸收峰；穀胱甘肽能引起NBD-SCN的顏色變化從無色變為黃色，吸收光譜會在420 nm處產生新的吸收峰。此外，NBD-SCN對生物硫醇的螢光表現顯示高選擇性：當NBD-SCN 加入10當量的半胱氨酸和高半胱氨酸反應後的溶液螢光強度分別為650倍和798倍。由半胱氨酸和高半胱氨酸的校正曲線計算後獲得的偵測極限分別為14.4 nM和10.8 nM。並利用螢光顯微鏡觀察細胞內生物硫醇的螢光影像。

We designed and synthesized a hydrophilic probe, 7-nitro-2,1,3-benzoxadiazol-4-yl thiocyanate (NBD-SCN), that can detect four specific biothiols [hydrogen sulfide (H2S), cysteine (Cys), homocysteine (Hcy) and glutathione (GSH)] on the basis of colorimetric and fluorescent methods. Especially, the probe can distinguish three biothiols by observing the remarkable change of the visible color via naked eyes and quantitative analysis utilizing UV-Visible spectrophotometer. H2S induce a distinct color change from colorless to violet and absorption bands shift to 530 nm. The relationship between absorbance and concentration of H2S presents an excellent linear correlation and shows a detection limit of 0.28 µM. Cys and Hcy induce a distinct color change from colorless to orange and absorption bands shift to 480 nm. GSH induce a distinct color change from colorless to yellow and absorption bands shift to 420 nm. In addition, NBD-SCN displays a high selectivity for Cys and Hcy in fluorescent enhancement. NBD-SCN exhibited 650-fold and 798-fold enhancement in fluorescence intensity by presence of 10 equiv. Cys and Hcy. The relationship between fluorescence intensity and concentration of Cys and Hcy presents an excellent linear correlation and shows a detection limit of 14.4 nM and 10.8 nM. The fluorescent images of biothiols in living cells have also been demonstrated.