Search

A straightforward, two step method for the self-assembly of single-walled carbon nanotubes (SWNTs) between gold electrodes is presented. The technique utilizes the hybridization between short complementary DNA sequences located on metal contacts and SWNTs. The new technique enables simple production of hundreds of devices with high yields. The electrical characteristics are shown to depend strongly on the existence of the chemical binding group, and are controlled by the transport through these groups. The current measured is larger by two orders of magnitude than the values reported for direct metal-SWNT contacts.

Self-assembled carbon-nanotube-based field-effect transistors (CNTFETs) were produced with high yield using the natural process of DNA hybridization. In principle, the devices made by this method behave like those made using direct metal-carbon nanotube contacts. The inverse subthreshold slope of the CNTFETs depends on the source-drain voltage applied to the device, confirming that the conductance of CNTFETs is determined by the Schottky barriers at the interfaces between the CNTs and the gold electrodes.

Self-assembled patterned multilayers may be fabricated using DNA monolayers and the orchestrated reactions of DNA-modifying enzymes. To demonstrate this approach, DNA monolayers were formed on silicon and cleaved quantitatively with a restriction enzyme. Subsequently, fluorescently labeled nucleotides were covalently incorporated to the cleaved DNA. Nucleotide addition was shown to be highly selective according to the sequence at the cleavage site, and no nonspecific adsorption to the surface was observed. The dual action of the DNA-modifying enzymes was quantitative and could be utilized in the fabrication of multilayered structures. Other DNA-modifying enzymes can be exploited in this manner to enrich the repertoire of self-assembly supramolecular structure fabrication.

A straightforward method for the self assembly of single walled carbon nanotubes (SWNTs) between gold electrodes was developed. The technique utilizes the hybridization between short complementary DNA sequences located on metal contacts and SWNTs. The new technique enables simple production of hundreds of devices with high yields. The electrical characteristics are shown to depend strongly on the existence of the chemical binding groups at the contacts as well as along the tubes. This technique was used to drive the self assembly of SWNT-based field effect transistors (CNTFETs). In principle, the devices made by this method behave like those made using direct metal–carbon nanotube contacts. The inverse subthreshold slope of the CNTFETs depends on the source–drain voltage applied to the device, confirming that the conductance of CNTFETs is determined by the Schottky barriers at the interfaces between the CNTs and the gold electrodes.