Leiden Institute of Physics, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands.
Nano Lett. 2013 Mar 13;13(3):980-6. doi: 10.1021/nl3040509. Epub 2013 Feb 8.
We report a novel technique for long-term parallel three dimensional (3D)-tracking of gold nanorods in live cells with nanometer resolution. Gold nanorods feature a strong plasmon-enhanced two-photon luminescence, can be easily functionalized, and have been shown to be nontoxic. These properties make gold nanorods very suitable for in vivo two-photon luminescence microscopy. By rapid multifocal scanning, we combine the advantages of 3D molecular tracking methods using wide-field imaging with the advantages of two-photon microscopy. Isolated gold nanorods can be localized with a resolution of 4 nm in the xy-plane and 8 nm in the z-direction. The polarization-dependence of the two-photon luminescence signal can be used to resolve the angular orientation, even when two gold nanorods are separated by less than the diffraction limit. Individual nanorods in live U2OS cells could be followed in 3 dimensions for over 30 min, with a photon noise limited accuracy, and a time resolution of 50 ms in 2D and 500 ms in 3D.
我们报告了一种新的技术，可用于在活细胞中以纳米分辨率进行长达 3D 跟踪的新型金纳米棒。金纳米棒具有强烈的等离子体增强双光子荧光，易于功能化，并且已被证明是无毒的。这些特性使金纳米棒非常适合用于体内双光子荧光显微镜。通过快速多焦点扫描，我们将使用宽场成像的 3D 分子跟踪方法的优势与双光子显微镜的优势相结合。在 xy 平面上的分辨率为 4nm，在 z 方向上的分辨率为 8nm，可对孤立的金纳米棒进行定位。双光子荧光信号的偏振依赖性可用于解析角度方向，即使两个金纳米棒之间的距离小于衍射极限也是如此。在活的 U2OS 细胞中，单个纳米棒可以在 3 个维度上进行超过 30 分钟的跟踪，具有光子噪声限制的准确性，在 2D 中的时间分辨率为 50ms，在 3D 中的时间分辨率为 500ms。
