Department of Physics and Center for NanoScience, LMU Munich, Amalienstrasse 54, 80799Munich, Germany.
Department of Physics and Debye Institute for Nanomaterials Science, Utrecht University, Princetonplein 1, 3584 CCUtrecht, The Netherlands.
Nano Lett. 2023 Feb 22;23(4):1236-1243. doi: 10.1021/acs.nanolett.2c04299. Epub 2023 Feb 6.
Atomic force microscopy (AFM) is a powerful technique for imaging molecules, macromolecular complexes, and nanoparticles with nanometer resolution. However, AFM images are distorted by the shape of the tip used. These distortions can be corrected if the tip shape can be determined by scanning a sample with features sharper than the tip and higher than the object of interest. Here we present a 3D DNA origami structure as fiducial for tip reconstruction and image correction. Our fiducial is stable under a broad range of conditions and has sharp steps at different heights that enable reliable tip reconstruction from as few as ten fiducials. The DNA origami is readily codeposited with biological and nonbiological samples, achieves higher precision for the tip apex than polycrystalline samples, and dramatically improves the accuracy of the lateral dimensions determined from the images. Our fiducial thus enables accurate and precise AFM imaging for a broad range of applications.
原子力显微镜（AFM）是一种强大的技术，可用于以纳米分辨率成像分子、大分子复合物和纳米粒子。然而，AFM 图像会因使用的探针形状而失真。如果可以通过扫描具有比探针更尖锐且高于感兴趣物体的特征的样品来确定探针形状，则可以对这些失真进行校正。在这里，我们提出了一种 3D DNA 折纸结构作为用于探针重建和图像校正的基准。我们的基准在广泛的条件下是稳定的，并且在不同高度具有锐利的台阶，使得仅从十个基准中就可以可靠地重建探针。该 DNA 折纸结构很容易与生物和非生物样品共沉积，比多晶样品具有更高的探针尖端精度，并极大地提高了从图像确定的横向尺寸的准确性。因此，我们的基准能够实现广泛应用的准确和精确的 AFM 成像。
