DNA nanowires

A last comment is due on the need for progress in the investigation tools. Further development in the study of potential DNA nanowires requires the advancement of synthesis procedures for the structural modifications, and an extensive effort in X-ray and NMR characterization. Concerning direct conductivity measurements, techniques for deposition of the molecules onto inorganic substrates and between electrodes must be optimized. Moreover,... 

Figure 9.17 AFM images of PPy-DNA nanowires and nanopores on a SiOJSi surface (a) nanowires observed 3 h after preparation (b) and (c) two representative images of nanorope samples observed after standing for 24 h. (Reprinted with permission from Advanced Functional Materials, Self-Assembly of DNA-Templated Polypyrrole Nanowires Spontaneous Formation of Conductive Nanoropes by S. Pruneanu, S. A. Farha Al-Said, L. Dongetal., 18, 16, 2444-2454. Copyright (2008) Wiley-VCH)...

In addition to synthetic polymer stmctures, highly aligned DNA nanowires (i.e., spokes) were successfully created by confining aqueous DNA solutions to a curve-on-flat geometry (i.e., sphere-on-flat or cylinder-on-flat) during evaporation (Fig. 3.13) [140], Unlike coffee-ring structures (or stripes), DNA nanowires formed perpendicular to the contact line. The extremities of DNA were able to anchor to the... 

Nakao H, Gad M, Sugiyama S, Otobe K, Ohtani T (2003) Transfer-printing of highly aligned DNA nanowires. J Am Chem Soc 125 7162-7163... 

Silver/DNA nanowire short sohd two exper. hquid/sol n 2.3.1... 

Fig. 5. 12 AFM and SNOM images of PPhenaz-TMA/DNA nanowires before eind after immersion in an Au + solution, (a) AFM topographic image and (b) SNOM image of PPhenaz-TMA/DNA nanowires before treatment, (c) AFM topographic image and (d) SNOM image of PPhenaz-TMA/DNA nanowires after treatment. Reprinted with permission from [98]. Copyright (2010)...

Bates et al. reported the construction and characterization of a gold nanoparticle wire assembled using Mg -dependent RNA-RNA interactions for the future assembly of practical nanocircuits [31]. They used magnesium ion-mediated RNA-RNA loop-receptor interactions, in conjunction with 15 nm or 30 nm gold nanoclusters derivatized with DNA to prepare self-assembled nanowires. A wire was deposited between lithographically fabricated nanoelectrodes and exhibited non-linear activated conduction by electron hopping at 150-300 K (Figure 16). 

Fig. 8.16 TEM image showing nanowires formed by wrapping X-DNA with an outer nanoshell of AMP (scale bar = 500nm).

Au-nanopartide nanowires based on DNA and polylysine templates. Angewandte Chemie-International Edition, 41, 2323-2327. 

Monson, C.F. and Woolley A.T. (2003) DNA templated construction of copper nanowires. Nano Letters, 3,... 

Hahm, J.-i. Lieber, C. M. 2004. Direct ultrasensitive electrical detection of DNA and DNA sequence variations using nanowire nanosensors. Nano Lett. 4 51-54. 

Stoltenberg RM, Woolley AT (2004) DNA-templated nanowire fabrication. Biomed Microdevices 6 105-111... 

Yan H, Park SH, Finkelstein G, Reif JH, LaBean TH (2003).DNA-templated self-assembly of protein arrays and highly conductive nanowires. Science 301 1882-1884. 

Theoretical Understanding of Charge Transport in DNA-based Nanowires... 

Does anyone actually use nanowires Well, Dr. Ock in Spiderman 2 claimed to use nanowires to connect his neural circuitry to a machine circuit. In fact, silicon nanowires have recently been used to build sensors for DNA. The sensors are designed to detect the presence of mutations in a cystic fibrosis gene. Nano Letters 2004, 4, 51 -54]... 

Indeed, substantial progress in the application of DNA as a template for the bottom-up construction of metallic NPs or nanowire circuitry, and the assembly of nanoscale miniaturized devices, was demonstrated in the past decade.90... 

The synthesis of conductive metallic nanowires that bridged two microelectrodes separated by a gap of 12-16 im was demonstrated by the growth of a silver nanowire on a DNA template that bridged the gap (Fig. 12.26).92 Short thiolated nucleic acids (12 bases long) were attached to the microelectrodes, and these acted as sticky ends for the hybridization of /.-DNA that bridged the gap. The association of Ag+ to the phosphate groups of the template, followed by their reduction with hydroquinone under basic conditions, resulted in the formation of Ag° nanoclusters on the DNA template. The subsequent enlargement of the Ag° seeds by the catalytic reduction of Ag+ by hydroquinone, under acidic conditions, yielded continuous Ag nanowires with a width of ca. lOOnm. The nanowires revealed nonlinear I—V... 

The bottom-up synthesis of metallic nanowires was further applied to construct a nanotransistor device.93 The sequence-specific winding of the homologous nucleic acid carried by the RecA-protein into the duplex DNA was used to address the nucleic acid/protein complex on the DNA scaffold (Fig. 12.27). The subsequent association of the anti-RecA antibody to the protein DNA complex, followed by the association of the biotinylated antiantibody, and the linkage of streptavidin-modified carbon nanotube deposited the tubes in the specific domain of the DNA scaffold. The further... 

Figure 12.26 Construction of a nanowire bridging two microelectrodes by the deposition of Ag+ ions on a bridging DNA strand, followed by their chemical reduction to the metallic agglomerate.

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