Takuya Hayashida

Publications (2)5.2 Total impact

• Article: Controlling the adsorption and desorption of double-stranded DNA on functionalized carbon nanotube surface.

  Daisuke Nii, Takuya Hayashida, Kazuo Umemura
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  ABSTRACT: We demonstrated controlled adsorption and desorption of double-stranded DNA (dsDNA) on single-walled carbon nanotube (SWNT) surface functionalized with polyethyleneglycol (PEG SWNT). First, when dsDNA molecules were mixed with the PEG SWNT solution, the DNA molecules spontaneously adsorbed onto the PEG SWNT surface and formed dsDNA-PEG SWNT conjugates without sonication. Next, we succeeded in detaching the dsDNA adsorbed on PEG SWNT by annealing at 95°C for 30min. These results were confirmed using atomic force microscopy, agarose gel electrophoresis, and micro-Raman spectroscopy. In contrast, when we used the usual SWNT produced by the high-pressure carbon monoxide method (HiPco SWNT), the DNA molecules were fragmented during the adsorption process as sonication was necessary for the hybridization of DNA-SWNT conjugates. Furthermore, detachment of DNA molecules from HiPco SWNT by annealing was impossible. Our method may be useful for developing DNA devices using SWNTs as substrates when it is combined with previously established various biochemical techniques.
  Colloids and surfaces. B, Biointerfaces 02/2013; 106C:234-239. · 2.60 Impact Factor
• Article: Surface morphology of hybrids of double-stranded DNA and single-walled carbon nanotubes studied by atomic force microscopy.

  Takuya Hayashida, Kazuo Umemura
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  ABSTRACT: We examined the formation of hybrids of double-stranded DNA (dsDNA) and single-walled carbon nanotubes (SWNTs), which has not been well investigated yet. In particular, the adsorption of dsDNA onto SWNT produced by chemical vapor deposition (CVD) was examined for the first time. When small amount of dsDNA was mixed with CVD SWNT, well dispersed hybrids with smooth surfaces were observed by atomic force microscopy (AFM). Through a comparison of dsDNA, single-stranded DNA (ssDNA), CVD SWNT, and high-pressure carbon monoxide process (HiPco) SWNT, we found that the surface morphology of the hybrids was independent of the DNA type. Even when sonicated salmon testes DNA, which has a random sequence and length, was employed, smooth surfaces were obtained on the dsDNA-CVD hybrids as well as on the ssDNA-CVD hybrids. The ratio of monodispersed SWNT and bundled SWNT in a dispersion solution was also not affected by the DNA type. In contrast, the quantity of the fabricated hybrids was affected by the types of DNA especially when HiPco SWNT was used. Our results indicated that characteristic features of the dsDNA-CVD hybrids and provide an enhanced understanding of the adsorption mechanism of dsDNA onto SWNTs.
  Colloids and surfaces. B, Biointerfaces 06/2012; 101C:49-54. · 2.60 Impact Factor