碳纳米管原子力显微镜针尖对脱氧核糖核酸高分辨率成像研究

Nanoscale Imaging of Deoxyribonucleic Acid in the Liquid Using Carbon Nanotube Probes

运用自制的碳纳米管原子力显微镜针尖,在液体中观察了脱氧核糖核酸(DNA)分子的精细结构。结果表明,运用碳纳米管针尖获得的DNA分子的高度与电子显微镜的结果非常接近,且没有造成样品的变形损伤;碳纳米管针尖得到的DNA分子的宽度与真实值相近,减小了原子力显微镜成像的增宽效应,这是用传统的硅针尖无法获得的。DNA分子精细结构的高分辨率图像的获得为研究其功能提供了有价值的信息。

The carbon nanotube （CNT） probes are used to observe the details in deoxyribonucleic acid （DNA） molecules under atomic force microscope （AFM） tapping mode in liquid. Long-range forces, which affect AFM measurements, can be drastically reduced by CNT tip especially in aqueous solution. The results show that when a carbon nanotube tip is used, AFM images visualizes the detailed structure of DNA, and its size is consistent with model proposed by crystal structure studies. These results cannot be reproduced using conventional AFM silicon probes. Carbon nanotube tip can be a powerful tool for the analysis of the detailed structure of biological materials and the relationship between the structure and function of DNA molecule.