Schmutz J-E, Hölscher H, Ebeling D, Schäfer M M, Anczykowski B
Center for Nanotechnology (CeNTech), Heisenbergstr. 11, 48149 Münster, Germany.
Ultramicroscopy. 2007 Oct;107(10-11):875-81. doi: 10.1016/j.ultramic.2007.04.015. Epub 2007 May 5.
Self-assembled monolayers of DPPC and DNA adsorbed on mica are examined by dynamic force spectroscopy under ambient conditions. By a systematic recording of the frequency shift caused by the tip-sample interaction we determine the corresponding tip-sample potential and force curves. In difference to the conventional measurement of force-vs.-distance curves this technique allows the continuous measurement of tip-sample forces without instabilities caused by a jump-to-contact. Due to the systematic mapping of the tip-sample interaction we are able to compute contour maps of the tip-surface potential of the DPPC films and to extract local properties like contact stiffness and adhesion force. The lateral resolution capabilities of the introduced spectroscopy method are examined by the example of lambda phage DNA.
在环境条件下，通过动态力谱对吸附在云母上的二棕榈酰磷脂酰胆碱（DPPC）和DNA的自组装单分子层进行了研究。通过系统记录由针尖-样品相互作用引起的频率偏移，我们确定了相应的针尖-样品势和力曲线。与传统的力-距离曲线测量不同，该技术允许连续测量针尖-样品力，而不会因接触跳跃而产生不稳定性。由于对针尖-样品相互作用进行了系统映射，我们能够计算DPPC膜的针尖-表面势的等高线图，并提取诸如接触刚度和粘附力等局部性质。以λ噬菌体DNA为例，研究了所引入的光谱方法的横向分辨率能力。
