Nanoscale imaging of deoxyribonucleic acid in the liquid using carbon nanotube probes

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.