Recently, nanometer-scale electronic devices have been widely investigated. One of the most promising fields, molecular electronics using single DNA nanowires are very attractive. DNA is expected to realize nanometer scale electronics circuits as nanowires and templates for deposition of functional materials. Therefore, manipulation and fabrication techniques of the DNA wires on substrates are very important to form a designed template for nanometer scale electronic circuits. However, as for the fabrication process using AFM scratching1, it is difficult to cut the DNA wire without dragging the wire due to its viscoelasticity.
Here we propose a novel AFM cutting process of DNA nano wires without dragging. Stretched DNA nano wires were prepared by drop the DNA solution on the polycarbonate substrate, and then sucked up with a pipet2. The DNA molecules on the surfaces are deteriorated by irradiation of lights. In order to make the DNA wire to be fragile, two treatment methods were performed. As a first method, irradiation of 254 nm ultraviolet rays, corresponding to absorbance peak of DNA, was performed to deteriorate the DNA molecules. After the treatment process of the UV light irradiation, the DNA wires were easily cut by AFM scratching without dragging the wire.
As a second method, dyed DNA molecules using YOYO1 was irradiated with 488 nm argon ion laser. After the irradiation process, the treated DNA wires could be easily cut by AFM scratching without dragging. Therefore those processes are very useful for controllable modification of DNA nano wire.
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