A Novel Nitric Oxide Fluorescent Probe Based On Signaling Mechanism Of C=N Isomerization

As an important cellular messenger and effector molecule, NO (nitric oxide) mediates and regulates a variety of physiological functions, and it plays an important role in the cardiovascular system, neuroscience system, respiratory and digestive system. We found that numerous pathological conditions including carcinogenesis, septicshock, pregnancy's hypertension and neurodegradation have been associated with the misregulation of NO production. However, due to the low concentration and rapid diffusion speed of nitric oxide in vivo and living cells, common nitric oxide probe can't detect nitric oxide timely and effectively. In order to study the multiple biological role of NO in biology, so designing a new NO probe which can detect NO more sensitively, specific and rapidly is imperative. Fluorescent compounds with unbridged C=N structure construct the predominant decay process in the excited states, resulting in fluorescence quenched. And due to the suppression of C=N isomerization in the excited states, fluorescence of fluorescent analogues with covalently bridged C=N structure dramatically increases. So we design and synthesis a novel nitric oxide fluorescent probe based on signaling mechanism of C=N Isomerization. Compared with the conventional NO fluorescent probe, this probe has the lower background signal, higher fluorescence quantum yield, better light stability, and the fluorescence intensity less influenced by the environment and PH.