以修飾碳氮雙鍵在 β位-BODIPY 之衍生物作為高選擇性次氯酸根離子螢光感測分子之合成與應用

Abstract

本篇論文以 BODIPY 的衍生物 HBP以及BODH 作為次氯酸根螢光感測分子，二者在多種的活性氧化物、氮化物下對次氯酸根離子具有高度的選擇性與靈敏度，並且在偵測到次氯酸根離子後會有強大的綠色螢光放射，以達到辨識的效果。 在兩種螢光感測分子的設計上，於 BODIPY 的 β-位置上修飾一個帶有非橋接 (unbridged) 碳氮雙鍵的官能基團，由於非橋接碳氮雙鍵的異構化導致螢光放射的淬熄，使得感測分子本身幾乎沒有螢光放射。然而當感測分子 HBP 與次氯酸根離子反應後，會行分子內氧化環化的動作，使得非橋接的碳氮雙鍵變成橋接 (bridged) 的碳氮雙鍵，進而阻斷螢光淬熄的機制，使得BODIPY的螢光被放射出來；感測分子 BODH 則是利用次氯酸根離子的氧化力，將非橋接的碳氮雙鍵氧化成醛官能基，移除掉螢光淬熄的機制，而達到螢光放射的效果。 此外，兩感測分子更可進一步應用於細胞實驗，利用共軛焦顯微鏡，可以成功觀測小鼠巨噬細胞內次氯酸根離子的分布。

In this thesis, we used the BODIPY derivatives HBP and BODH as the fluorescent probes for HOCl. Both of them exhibited high selectivity and high sensitivity for hypochlorite ions over others ROS (reactive oxygen species) and RNS (reactive nitrogen species). The strong green fluorescence of BODIPY is restored after reaction with hypochlorite ions. The design of two fluorescent probe is based on the functionalization with unbridged C=N in β-position of BODIPY. It was found that unbridged C=N structure will quench the fluorescent due to the C=N isomerization, which is the predominant decay process of excited states. However, when the reaction of the probe HBP with hypochlorite ions, a oxidative intramolecular cyclization will convert the unbridged C=N to a bridged C=N which suppressed the C=N isomerization and then restore the fluorescence. For BODH, the unbridged C=N contained functional group will be converted to aldehyde by the oxidation of hypochlorite ions. Because the fluorescent quenching mechanism was terminated, the fluorescence of BODIPY was restored. Finally, confocal microscopy imaging using RAW264.7 cells showed that the two probes could be used as effective fluorescent probes for detecting HOCl in living cells.