Fluorescence of Single Molecules in Polymer Films: Sensitivity of Blinking to Local Environment

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• 作者：John N. Clifford ; Toby D. M. Bell ; Philip Tinnefeld ; Mike Heilemann ; Sergey M. Melnikov ; Jun-ichi Hotta ; Michel Sliwa ; Peter Dedecker ; Markus Sauer ; Johan Hofkens ; Edwin K. L. Yeow
• 刊名：Journal of Physical Chemistry B
• 出版年：2007
• 出版时间：June 28, 2007
• 年：2007
• 卷：111
• 期：25
• 页码：6987 - 6991
• 全文大小：153K
• 年卷期：v.111,no.25(June 28, 2007)
• ISSN：1520-5207

文摘

The single-molecule fluorescence blinking behavior of the organic dye Atto647N in various polymer matrixessuch as Zeonex, PVK, and PVA as well as aqueous media was investigated. Fluorescence blinking withoff-times in the millisecond to second time range is assigned to dye radical ions formed by photoinducedelectron transfer reactions from or to the environment. In Zeonex and PVK, the measured off-time distributionsshow power law dependence, whereas, in PVA, no such dependence is observed. Rather, in this polymer,off-time distributions can be best fitted to monoexponential or stretched exponential functions. Furthermore,treatment of PVA samples to mild heating and low pressure greatly reduces the frequency of blinking events.We tentatively ascribe this to the removal of water pockets within the polymer film itself. Measurements ofthe dye immobilized in water in the presence of methylviologen, a strongly oxidizing agent, reveal simpleexponential on- and off-time distributions. Thus, our data suggest that the blinking behavior of single organicmolecules is sensitive to their immediate environment and, moreover, that fluorescence blinking on- andoff-time distributions do not inherently and uniquely obey a power law.