Reduction of Long-range Interactions using Carbon Nanotube Probes in Biological Systems

Carbon nanotubes (CNT) have been used as tips in non-contact atomic force microscopy (NC-AFM) to observe biomolecules including deoxyribonucleic acid (DNA) molecules. Adhesion and electrostatic forces, which affect NC-AFM measurements even in vacuum condition, can be drastically reduced by using a CNT tip without thermal treatments for samples. Consequently, stable imaging of DNA molecules was performed under the presence of a water layer and various surface charges on the substrate. This is highly advantageous for imaging biomolecules, which are denatured easily by thermal treatment.