Unique Optical Oxygen-Sensing Performance of [Ru(IP)2(HNAIP)]2+ during the Groove-Binding-Induced B-to-Z DNA Conformational Transition

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• 作者：Linlin Chen ; Hui Chao ; Qianwen Zhao ; Hong Li
• 刊名：Inorganic Chemistry
• 出版年：2015
• 出版时间：September 8, 2015
• 年：2015
• 卷：54
• 期：17
• 页码：8281-8287
• 全文大小：470K
• ISSN：1520-510X

文摘

The oxygen-sensing performance of [Ru(IP)₂(HNAIP)]²⁺ (Ru1, IP = imidazo[4,5-f][1,10]phenanthroline and HNAIP = 2-(2-hydroxy-1-naphthyl)imidazo [4,5-f][1,10]phenanthroline) in the presence of DNA conformational transition has been investigated by means of absorption spectroscopy, steady-state and time-resolved fluorescence spectroscopies, and circular dichroism spectroscopy. Ru1 shows a good linear response toward oxygen between pure nitrogen and pure oxygen with an on鈥搊ff emission intensity ratio (I₀/I₁₀₀) of up to 9.3 via a dynamic quenching mechanism. Compared with [Ru(IP)₂(DHPIP)]²⁺ (Ru2, DHPIP = 2-(2,4-dihydroxyphenyl)imidazo[4,5-f][1,10]phenanthroline, I₀/I₁₀₀ = 5.8), the HNAIP ligand endows Ru1 with favorable oxygen binding sites to achieve larger energy and electron transfer rates. Simultaneously, Ru1 can induce the B-to-Z DNA conformational transition via a groove interaction with an intrinsic binding constant (K_b) of 7.9 脳 10⁴ M^鈥?, whereas there is no same phenomenon for Ru2 intercalated into DNA (K_b = 3.3 脳 10⁵ M^鈥?). Furthermore, the B-to-Z DNA conformational transition is interestingly found to decrease the Ru1-based oxygen-sensing rate by about 33%.