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Abstract：
A superhydrophobic (SH) sandwich system has been developed to enable \"contact-free\" airborne singlet oxygen (1O2) delivery to a water droplet. The contact-free feature means that the sensitizer is physically separated from the droplet, which presents opportunities for photodynamic therapy (PDT). Trapping of airborne 1O2 in a H2O droplet residing on a lower SH surface was monitored with 9,10-anthracene dipropionate dianion by varying distances to an upper 1O2-generating surface. Short distances of 20 μm efficiently delivered airborne 1O2 to the droplet in single-digit picomolar steady-state concentrations. Delivery decreases linearly with distance, but 50% of the 1O2 steady-state concentration is trapped at a distance of 300 μm from the generating surface. The 1270 nm luminescence intensity was measured within the SH sandwich system, confirming the presence of airborne 1O2. Physical quenching of 1O2 to ground-state 3O2 by the water droplet itself and both physical and chemical quenching of 1O2 by the water droplet containing the trap 9,10-anthracene dipropionate dianion are observed. Unlike a majority of work in the field of PDT with dissolved sensitizers, where 1O2 diffuses short (hundreds of nanometers) distances, we show the delivery of airborne 1O2 via a superhydrophobic surface is effective through air in tenths of millimeters distances to oxidize an organic compound in water. Our results provide not only potential relevance to PDT but also surface bacterial inactivation processes.
摘要：
已开发出超疏水（SH）三明治系统，以使“无接触”空气中的单线态氧（1O2）输送到水滴。无接触特征意味着敏化剂与液滴物理分离，这为光动力疗法（PDT）提供了机会。用9,10-蒽二丙酸二阴离子通过改变到产生1O2的上表面的距离来监测将空气中的1O2捕获在位于SH下表面的H2O液滴中。20μm的短距离有效地将空气中的1O2以单位数皮摩尔稳态浓度输送到液滴。交付量随距离线性减少，但是50％的1O2稳态浓度被捕获在距生成表面300μm的距离处。在SH夹心系统内测量1270nm的发光强度，确认空气中存在1O2。观察到水滴本身将1O2物理猝灭为基态3O2，以及包含陷阱9,10-蒽二丙酸二阴离子的水滴对1O2的物理和化学猝灭。与PDT领域中使用溶解的敏化剂的大多数工作不同，其中1O2扩散短（数百纳米）的距离，我们表明，通过超疏水表面输送空气中的1O2是有效的，通过空气在十分之一毫米的距离氧化水中的有机化合物。我们的结果不仅提供了与PDT的潜在相关性，而且还提供了表面细菌灭活过程。
