Evidence that pyrene excimer formation in membranes is not diffusion-controlled.
Evidence that pyrene excimer formation in membranes is not diffusion-controlled.
复制标题
有证据表明膜中芘准分子的形成不受扩散控制。
DOI：
10.1016/0005-2736(86)90327-5
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发表时间：
1986
期刊：
影响因子：
--
通讯作者：
Barber,J
中科院分区：
文献类型：
--
作者：
Blackwell,MF;Gounaris,K;Barber,J
Kinetic and steady-state measurements of pyrene fluorescence in a variety of model membranes are evaluated in terms of the theory of collisional excimer formation. In the region of 10−3−0.1 M pyrene, molecular fluorescence decay in membranes in biphasic and the two component lifetimes do not depend on the pyrene concentration. The lifetime data are consistent with the rate constant for collisional excimer formation being of the order 106M−1·s−1or less. The concentration dependence of the component amplitudes is inconsistent with the theory of collisional excimer formation and suggests that pyrene exists in two forms in membranes: a slowly diffusing monomeric form and an aggregated form. The component of molecular fluorescence decay associated with aggregated pyrene is highly correlated with steady-state excimer fluorescence, suggesting that excimer fluorescence in membranes arises from aggregated pyrene in which excimers are formed by a static rather than a collisional mechanism. It is suggested that the concentration dependence of excimer to molecular fluorescence intensity ratios in membranes is related to the equilibrium constant for exchange between monomeric and aggregated pyrene forms rather than to the collisional excimer formation rate constant.
