DNA mediated self assembly of carbon nanotubes into nanorings

Carbon Nanotubes(CNT) are newly discovered nanomaterials with unique physical, chemical, electrical and optical characteristics and they have a variety of applications in different areas. However, due to their strong affinity towards each other to form aggregates, it becomes difficult to extend their use into a wide range of applications. DNA attracts the attention of researchers with its ability to disperse nanotubes. DNA-CNT interaction involves two different approaches. In non-covalent approach, DNA wraps around the Carbon Nanotubes. This approach protects the intrinsic properties of the carbon nanotubes but offer limited potential for self-assembly research. On the other hand, covalent DNA binding to CNTs allows the use of DNA hybridization properties and has the potential to produce complex shapes. In this work, Single Walled Carbon Nanotubes (SWCNTs) were functionalized with carboxyl acid groups and oligodeoxynucleotides(ODNs) were covalently bound to them. Nanoring structures were formed by binding two different ODN bound SWCNTs together with an ODN linker. These nanoring structures and the factors affecting them were studied under Atomic Force Microscopy(AFM). The knowledge obtained from this work shows the preparation of nanorings using DNA mediated self-assembly of SWCNTs, which can be used for designing more complex structures, photothermal therapy, nanoelectronics, gene delivery.