DNA-Directed Self-Assembly of Microscopic 1-D Carbon Nanotube Wire

Molecular wire construction using DNA-directed self-assembly of multi-walled carbon nanotubes (MWNTs) has been attempted. MWNTs were selected owing to their exceptional electrical and structural properties. DNA, which possesses specific molecular recognition properties, served as the engine for the assembly. Non-crosshybridizing (NCH) sequences were designed to impart specificity and high throughput reaction. Stepwise manufacturing of the wire was accomplished by first functionalizing the NCH 20 base pair single-stranded sequences to the tips of MWNT using amide linkage. The adducts were then utilized to self-assemble 1D nanotube wire through DNA hybridization reactions between two complementary ssDNAs functionalized to the MWNT tips. TEM, epi-fluorescent microscopy and AFM analyses showed successful assemblies of micrometer-scale 1D MWNT-DNA wires, ranging from 2.7-20 mum. The results demonstrate great potentials of the DNA-guided self-assembly process, which would provide an uncomplicated, versatile and inexpensive way to manufacture micrometer-scale molecular wires.