Controlled dispersion and purification of protein-carbon nanotube conjugates using guanidine hydrochloride
| Autor: | Takeshi Akasaka, Ryuuichi Ueki, Jun-ichi Fujita, Yosuke Miyazawa, Yutaka Maeda, Kentaro Shiraki, Atsushi Hirano, Xiaofei Yuan |
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| Rok vydání: | 2010 |
| Předmět: |
Nanotube
Drug Carriers Protein Denaturation Protein Folding Aqueous solution Nanotubes Carbon Organic Chemistry General Chemistry Carbon nanotube Biosensing Techniques Hydrogen-Ion Concentration Catalysis law.invention chemistry.chemical_compound chemistry Chemical engineering law Organic chemistry Denaturation (biochemistry) Guanidine Drug carrier Hybrid material Protein adsorption |
| Zdroj: | Chemistry (Weinheim an der Bergstrasse, Germany). 16(40) |
| ISSN: | 1521-3765 |
| Popis: | For the development of biofunctional carbon nanotubes for biosensors, drug carriers, and nanobiocatalysts, their aggregation and biofouling in aqueous solutions are crucial problems because this behavior leads to a reduction of their excellent optical and electrical properties and nanoscale size effects. This paper presents a new method for enhancing the dispersibility of protein–carbon nanotube conjugates and for exfoliating the protein from the carbon nanotube sidewalls through controlling the concentration of guanidine hydrochloride (Gdn⋅HCl) in the solution. In medium concentrations (2–3 M) of Gdn⋅HCl, the dispersibility of protein–carbon nanotube conjugates was found to be substantially increased without denaturation or aggregation of the proteins. At higher concentrations (>6 M) of Gdn⋅HCl, pristine carbon nanotubes were precipitated instantly as a result of dissociation of the protein. These phenomena indicate that Gdn⋅HCl functions not only as a dispersion adjuvant for biofunctional protein–carbon nanotube conjugates, but also as a cleaning agent for the purification of biofouled carbon nanotubes. The dissociation concentrations of Gdn⋅HCl were higher than the midpoint of protein denaturation, suggesting that protein adsorption on carbon nanotubes is more stable than protein folding toward Gdn⋅HCl. |
| Databáze: | OpenAIRE |
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