Single-molecule fluorescence imaging has become an indispensable tool for almost all fields of research, from fundamental physics to the life sciences. Among its most important applications is single-molecule localization super-resolution microscopy (SMLM) (for example, photoactivated localization microscopy (PALM)¹, stochastic optical reconstruction microscopy (STORM)², fluorescent PALM (fPALM)³, direct STORM (dSTORM)⁴ and point accumulation for imaging in nanoscale topography (PAINT)⁵), which uses the fact that the centre position of a single molecule’s image can be determined with much higher accuracy than the size of that image itself. However, a big challenge of SMLM is to achieve super-resolution along the third dimension as well. Recently, metal-induced energy transfer (MIET) was introduced to axially localize fluorescent emitters^6,7,8,9. This exploits the energy transfer from an excited fluorophore to plasmons in a thin metal film. Here, we show that by using graphene as the ‘metal’ layer, one can increase the localization accuracy of MIET by nearly tenfold. We demonstrate this by axially localizing single emitters and by measuring the thickness of lipid bilayers with ångström accuracy.

从基本物理学到生命科学，单分子荧光成像已成为几乎所有研究领域必不可少的工具。其最重要的应用是单分子定位超分辨率显微镜（SMLM）（例如，光激活定位显微镜（PALM）¹，随机光学重建显微镜（STORM）²，荧光PALM（fPALM）³，直接STORM（dSTORM））⁴和点累加，用于纳米形貌成像（PAINT）⁵），利用这样一个事实，即可以以比该图像本身的大小高得多的精度确定单个分子图像的中心位置。但是，SMLM的一大挑战是也要在第三维上实现超分辨率。最近，金属诱导的能量转移（MIET）被引入以轴向定位荧光发射器^6,7,8,9。这利用了从激发的荧光团到薄金属膜中的等离激元的能量转移。在这里，我们表明，通过使用石墨烯作为“金属”层，可以将MIET的定位精度提高近十倍。我们通过轴向定位单个发射器并以ångström精度测量脂质双层的厚度来证明这一点。