Design and Synthesis of Fluorescent Chemosensors for Detection of HOCl and Their Applications in Living Cells
|摘要:||本論文以BODIPY和NBD為螢光基團，以硫原子和硒原子為辨識端，設計並合成出螢光化學感測分子BSP和NBDSe。此系列的螢光化學感測分子皆可以利用次氯酸的強氧化力來氧化其辨識端，使原本沒有任何螢光放射的BSP和NBDSe，分別產生橘黃色和綠色的螢光，其反應時間皆低於30秒，故可應用於快速的偵測和檢驗。此外，BSP和NBDSe在緩衝溶液中都具有良好的偵測能力，偵測極限分別為3.00 x 10-8 M和2.47 x 10-8 M，而且，在pH值約為7.0左右時，具有較為明顯的偵測效果。
BSP和NBDSe的偵測機制主要是藉次氯酸根的氧化力，使BSP上的硫原子和NBDSe上的硒原子反應，讓原先BSP的ICT機制和NBDSe的PET機制都被抑制，進而出現螢光的現象。接著，將BSP和NBDSe應用於細胞顯影實驗中，在老鼠巨噬細胞(Raw 264.7)中， BSP和NBDSe可有效的偵測次氯酸根離子，並可更進一步偵測由PMA刺激所產生的ROS和RNS。最後，由細胞毒性檢可知，當BSP和NBDSe之濃度達20 μM時，巨噬細胞的存活率仍超過80 %。|
In this thesis, BODIPY- based and NBD- based fluorescent chemosensors BSP and NBDSe were designed and synthesized for detection of HOCl. These chemosensors utilize the oxidation activity of HOCl to react with their recognition moieties, and produced significant fluorescence enhancement. To begin with, BSP and NBDSe displayed good selectivity in buffer solution and even much better at the pH value of 7.0, with detection limits of 3.00 x 10-8 M and 2.47 x 10-8 M respectively. The detection mechanisms of BSP and NBDSe were based on oxidation activity of HOCl. By reacting with sulfur of BSP and selenium of NBDSe, ICT mechanism of BSP and mechanism of NBDSe were interfered and thus fluorescence changes were observed. In addition, BSP and NBDSe were further applied in living cells. BSP and NBDSe were able to detect both HOCl and ROS stimulated by PMA in Raw 264.7. According to cytotoxicity tests, cell viabilities were above 80 %, when the concentrations of BSP and NBDSe were 20 μM.