DNA-Templated Carbon Nanotube Field-Effect Transistor

Abstract

The combination of their electronic properties and dimensions makes carbon nanotubes ideal building blocks for molecular electronics. However, the advancement of carbon nanotube-based electronics requires assembly strategies that allow their precise localization and interconnection. Using a scheme based on recognition between molecular building blocks, we report the realization of a self-assembled carbon nanotube field-effect transistor operating at room temperature. A DNA scaffold molecule provides the address for precise localization of a semiconducting single-wall carbon nanotube as well as the template for the extended metallic wires contacting it.Individual single-wall carbon nanotubes (SWNT) have been used to realize molecular-scale electronic devices such as singleelectron (1) and field-effect transistors (FET) (2). Several SWNT-based devices have been successfully integrated into logic circuits (3) and transistor arrays (4 ). However, the difficulty in precise localization and interconnection of nanotubes impedes further progress toward larger-scale integrated circuits.Self-assembly based on molecular recognition provides a promising approach for constructing complex architectures from molecular building blocks, such as SWNTs, bypassing the need for precise nanofabrication and mechanical manipulations (5). Biology, with its inherent self-assembly capabilities (6-13), is particularly attractive for this task. Biological recognition has been imparted to carbon nanotubes (14-18), but their self-assembly into functional devices and circuits has not yet been demonstrated. We present a framework for self-assembly of carbon nanotube-based electronics using DNA and homologous genetic recombination. A semiconducting SWNT was localized at a desired address on a DNA scaffold molecule using homologous recombination by the RecA protein from Escherichia coli bacteria (19). DNA metallization, with the RecA doubling as a sequence-specific resist (13), led to the formation of extended conductive wires that electrically contact the SWNT. The conduction through the SWNT was controlled by a voltage applied to the substrate supporting the structure.The SWNT-FET ( Fig. 1) was assembled via a three-strand homologous recombination reaction between a long double-stranded DNA (dsDNA) molecule serving as a scaffold and a short, auxiliary single-stranded DNA (ssDNA) (20). The assembly process was guided by the information encoded in these DNA molecules. The short ssDNA molecule was synthesized so that its sequence is identical to the dsDNA at the designated location of the FET. RecA proteins were first polymerized on the auxiliary ssDNA molecules to form nucleoprotein filaments (Fig. 1, step i), which were then mixed with the scaffold dsDNA molecules. A nucleoprotein filament bound a dsDNA molecule according to the sequence homology between the ssDNA and the designated address on the dsDNA (Fig. 1, step ii). The RecA later helped localize a SWNT at that address and protect the covered DNA segment against metallization (13). Figure ...

Nanowires and Carbon Nanotubes

“…1d), which resolve individual Si NWs within the transferred BBF, show that the Si NWs recorded from different areas of this large substrate are well aligned along the upward expansion direction of the bubble. Indeed, the angular deviation of the Si NWs is less than 108 over the entire 150-mmdiameter wafer and represents a very substantial advance over previous studies [4][5][6][7][8] .…”

“…To realize such applications, researchers have directed considerable effort to the development of methods of assembly that might ultimately lead to integrated systems. For example, there have been studies of individual or small numbers of NW and NT devices prepared by random deposition, electric field directed assembly 4 , flowassisted alignment 5 , and selective chemical and biological patterning 6,7 , and up to centimetre-scale assembly of NWs using the Langmuir-Blodgett technique 8 . However, it is still unclear whether these methods can be extended to large-scale assembly of NWs and NTs on both rigid and flexible substrates with controlled alignment and density.…”

DNA Functionalized Single-Walled Carbon Nanotubes for Electrochemical Detection

“…Many unique properties of DNA have inspired researchers to combine this biological material with SWNTs to explore its nonbiological applications, such as covalent conjugation 15 of DNA to oxidizing open ends of SWNTs for selfassembled molecular-scale electronic systems, noncovalent binding (π-stacking) of DNA to side walls of SWNTs for dispersion and separation of SWNTs, 16 and DNA-templated carbon nanotube field-effect transistors. 17 However, few reports are available about DNA-functionalized SWNTs for applications in electrochemical analysis. Recently, Zheng and Diner reported that they used DNA-carbon nanotube (CNT) hybrids to monitor electron transfer between small-molecule redox reagents and carbon nanotubes by using UV/vis/NIR absorbance spectra.…”

Liquid‐Phase Exfoliation of Nanotubes and Graphene

“…Additionally, if one chooses, oligonucleotides can be removed using small aromatic molecules such as rhodamine 6G or the complementary DNA strand, once any necessary processing is complete [99] . A variety of different applications, such as fibre spinning [102] ; self-assembled nanotube field-effect transistors [103] ; stabilization of colloidal particles [104] ; chemical sensing [105] ; and both medical diagnostic and biological fields [100,[106][107][108][109] have been investigated for DNA-dispersed SWNTs.…”