Biological Physics, School of Physics and Astronomy, University of Manchester, Oxford Rd., Manchester, M13 9PL, UK.
Photon Science Institute, University of Manchester, Oxford Rd., Manchester, M13 9PL, UK.
Sci Rep. 2018 Nov 16;8(1):16928. doi: 10.1038/s41598-018-35297-4.
Quenched Stochastic Optical Reconstruction Microscopy (qSTORM) was demonstrated with graphene oxide sheets, peptides and bacteria; a method of contrast enhancement with super-resolution fluorescence microscopy. Individual sheets of graphene oxide (GO) were imaged with a resolution of 16 nm using the quenching of fluorescence emission by GO via its large Resonant Energy Transfer (RET) efficiency. The method was then extended to image self-assembled peptide aggregates (resolution 19 nm) and live bacterial cells (resolution 55 nm, the capsular structure of E. coli from urinary tract infections) with extremely low backgrounds and high contrasts (between one and two orders of magnitude contrast factor improvements that depended on the thickness of the graphene oxide layer used). Graphene oxide films combined with STORM imaging thus provide an extremely convenient method to image samples with large backgrounds due to non-specifically bound fluorophores (either due to excess labelling or autofluorescent molecules), which is a common occurrence in studies of both biological cells and soft-condensed matter. The GO quenches the fluorescence across a thin layer at distances of less than 15 nm. Graphene oxide films coated with thin layers (≤15 nm) of polystyrene, polymethylmethacrylate and polylysine are shown to be effective in producing high contrast qSTORM images, providing a convenient modulation of sample/substrate interactions. The GO coatings can also provide an increased image resolution and a factor of 2.3 improvement was observed with the peptide fibres using a feature of interest metric,when there was a large non-specifically bound background.
被猝灭的随机光学重建显微镜（qSTORM）已在氧化石墨烯片、肽和细菌上得到证实；这是一种超分辨率荧光显微镜对比度增强的方法。通过氧化石墨烯的大共振能量转移（RET）效率来猝灭其荧光发射，从而对单个氧化石墨烯片进行成像，分辨率为 16nm。然后，该方法扩展到对自组装肽聚集体（分辨率 19nm）和活细菌细胞（分辨率 55nm，来自尿路感染的大肠杆菌荚膜结构）进行成像，具有极低的背景和高对比度（对比度因子提高了一到两个数量级，这取决于所使用的氧化石墨烯层的厚度）。氧化石墨烯薄膜与 STORM 成像相结合，因此提供了一种非常方便的方法来对由于非特异性结合的荧光团而具有大背景的样品进行成像（要么是由于过量标记或自发荧光分子），这在生物细胞和软凝聚态物质的研究中很常见。氧化石墨烯在距离小于 15nm 的薄层中猝灭荧光。研究表明，涂有聚苯乙烯、聚甲基丙烯酸甲酯和聚赖氨酸等薄层（≤15nm）的氧化石墨烯薄膜在产生高对比度 qSTORM 图像方面非常有效，可方便地调节样品/基底相互作用。当存在大的非特异性结合背景时，氧化石墨烯涂层还可以提供更高的图像分辨率，并且在使用感兴趣的特征的度量标准时，观察到肽纤维的分辨率提高了 2.3 倍。
