The use of single-molecule microscopy is introduced as a method to quantify the photophysical properties of supramolecular complexes rapidly at ultra low concentrations (<1 nM), previously inaccessible. Using a model supramolecular system based on the host–guest complexation of cucurbit[n]uril (CB[n]) macrocycles together with a fluorescent guest (Ant910Me), we probe fluorescent CB[n] host–guest complexes in the single molecule regime. We show quantification and differentiation of host–guest photophysics and stoichiometries, both in aqueous media and noninvasively in hydrogel, by thresholding detected photons. This methodology has wide reaching implications in aiding the design of next-generation materials with programmed and controlled properties.

中文翻译：

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超分子配合物的单分子化学计量

单分子显微镜的使用被引入作为一种在超低浓度（<1 nM）下快速量化超分子复合物光物理性质的方法，这在以前是无法实现的。使用基于葫芦[ n ]uril (CB[ n ])大环与荧光客体( Ant910Me )主客体络合的模型超分子系统，我们在单分子体系中探测荧光CB[ n ]主客体络合物。我们通过对检测到的光子进行阈值化，展示了在水介质和非侵入性水凝胶中主客体光物理和化学计量的量化和区分。这种方法对于帮助设计具有编程和受控特性的下一代材料具有广泛的影响。