AFM针尖对胶原样品表面一种损伤现象的研究

用AFM对吸附于云母表面的胶原蛋白的研究过程中，观察到一种AFM针尖对样品损伤现象。在小范围的扫描过程中．胶原蛋白在AFM针尖的作用下。产生了明显的移动。改变了其原来平整、均匀分布的表面特征。此现象文献中也曾有报道，在本实验中能重复出现。本文进一步分析讨论这种现象产生的原因，对比了不同成像模式下AFM针尖对样品表面的影响。结果表明，用Tapping Mode(TM)，扫描过程对样品表面几乎不产生影响，但是Non Contact Mode(NCM)在扫描过程中对样品表面产生了损伤作用。证明了TM模式更适合于对生物样品的研究。实验还发现这种损伤的程度和扫描范围的大小、针尖扫描的方向有着很大关系。

Study on a Damaging Phenomenon of AFM Tip on Surface of Collagen Layer

A damaging phenomenon of AFM tip to sample surface has been found during the study of collagen absorbed on the mica by means of Atomic Force Microscope (AFM). When the scan size was small, collagen fibrin apparently moved as a result of the AFM tip. The original characteristics on sample surface changed. This paper compared the effect of AFM tip to the sample surface under different imaging modes. The results showed that Tapping Mode (TM) hardly affected sample surface while Non contact Mode could damage the sample surface.So we concluded that TM was more suitable for the biological samples. We also found that the extent of damaging was in a close relationship with scan size and scan direction.