Solubilization of single-walled carbon nanotubes using a peptide aptamer in water below the critical micelle concentration.
The solubilizing ability of single-walled carbon nanotubes (SWCNTs) in water with several dispersants was investigated. Among the dispersants, including low-molecular-weight surfactants, peptides, DNA, and a water-soluble polymer, the peptide aptamer, A2 (IFRLSWGTYFS), exhibited the highest dispersion capability below the critical micelle concentration at a concentration of 0.02 w/v%. The dispersion of supernatant aqueous solution of SWCNTs containing aptamer A2 was essentially unchanged for several months after high-speed ultracentrifugation and gave rise to an efficient and stable dispersion of the SWCNTs in water. From the results of isothermal titration calorimetry and molecular dynamics simulations, the effective binding capability of A2 was due to π-π interaction between aromatic groups in the peptide aptamer and the side walls of SWCNTs. Interestingly, the peptide aptamer showed the possibility of diameter separation of semiconducting SWCNTs using a uniform density gradient ultracentrifuge. These phenomena are encouraging results toward an effective approach to the dispersion and separation of SWCNTs.
†Nano Medical Engineering Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Zha
Z
Li
‡Computational Biology Research Center, National Institute of Advanced Industrial Science and Technology, Koto, Tokyo 135-0064, Japan.|§Emergent Bioengineering Materials Research Team, RIKEN Center for Emergent Matter Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Tomoshi
T
Kameda
†Nano Medical Engineering Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Takashi
T
Isoshima
∥Department of Environmental Chemistry and Engineering, Graduate School of Interdisciplinary Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta, Yokohama 226-8501, Japan.
Eiry
E
Kobatake
⊥Carbon Nanomaterials Research Group, Nanosystem Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki 305-8562, Japan.
Takeshi
T
Tanaka
†Nano Medical Engineering Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.|§Emergent Bioengineering Materials Research Team, RIKEN Center for Emergent Matter Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.
Yoshihiro
Y
Ito
†Nano Medical Engineering Laboratory, RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.|§Emergent Bioengineering Materials Research Team, RIKEN Center for Emergent Matter Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan.|#Photocatalysis International Research Center, Research Institute for Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan.
Masuki
M
Kawamoto
D052158:Aptamers, Peptide / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D008823:Micelles; D037742:Nanotubes, Carbon / Q000737:chemistry*; D014867:Water / Q000737:chemistry*
D052158:Aptamers, Peptide; D008823:Micelles; D037742:Nanotubes, Carbon; D014867:Water; D002244:Carbon