Ijeri Vijaykumar S, Daasbjerg Kim, Ogilby Peter R, Poulsen Lars
Center for Oxygen Microscopy and Imaging, Department of Chemistry, University of Aarhus, Langelandsgade 140, DK-8000 Arhus, Denmark.
Langmuir. 2008 Feb 5;24(3):1070-9. doi: 10.1021/la7028577. Epub 2008 Jan 4.
Active spatial and temporal modulation of domains of singlet oxygen activity is demonstrated using electrochemical tools. Using singlet oxygen microscopy in photosensitized experiments, it is shown that singlet oxygen concentrations around an ultramicroelectrode can be controlled by applying a bias voltage to the electrode. Two phenomena that can be exploited separately or collectively are examined: (1) the singlet oxygen concentration can be altered by local oxidation or reduction of the photosensitizer, which is the precursor to singlet oxygen, and (2) the reduction of oxygen to produce the superoxide anion which, among other things, is an effective singlet oxygen quencher, results in a local decrease in the concentration of singlet oxygen around the electrode. Both of these phenomena depend significantly on the diffusion of molecules along concentration gradients established by the biased electrode. The results reported herein demonstrate that one can indeed exert local electrochemical control and readily manipulate the population of singlet oxygen produced in a photosensitized process.
利用电化学工具展示了单线态氧活性区域的主动时空调制。在光敏实验中使用单线态氧显微镜，结果表明通过向超微电极施加偏置电压，可以控制超微电极周围的单线态氧浓度。研究了两种可单独或共同利用的现象：（1）单线态氧的前体光敏剂的局部氧化或还原可改变单线态氧浓度，以及（2）氧还原产生超氧阴离子，超氧阴离子除其他作用外还是一种有效的单线态氧猝灭剂，这会导致电极周围单线态氧浓度局部降低。这两种现象都极大地依赖于分子沿偏置电极建立的浓度梯度的扩散。本文报道的结果表明，人们确实可以进行局部电化学控制，并轻松操纵光敏过程中产生的单线态氧数量。
