Reversible Biochemical Switching of Ionic Transport through Aligned Carbon Nanotube Membranes

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• 作者：P. Nednoor ; N. Chopra ; V. Gavalas ; L. G. Bachas ; and B. J. Hinds
• 刊名：Chemistry of Materials
• 出版年：2005
• 出版时间：July 12, 2005
• 年：2005
• 卷：17
• 期：14
• 页码：3595 - 3599
• 全文大小：252K
• 年卷期：v.17,no.14(July 12, 2005)
• ISSN：1520-5002

文摘

Synthetic nanopore membranes can be used to mimic ion channels provided that molecular transportthrough membranes is precisely gated with selective and reversible chemical interactions. Alignednanotubes of carbon or other inorganic materials can be assembled to construct higher-order supramoleculararchitectures using polymer films to force chemical flux through hollow cores. Open tips of carbonnanotubes (CNT) can be activated to have carboxylic groups, which can be easily derivatized with amolecule that binds to a bulky receptor that can open/close the pore entrance. In particular, the coreentrances of an aligned CNT membrane were functionalized with a desthiobiotin derivative that bindsreversibly to streptavidin, thereby enabling a reversible closing/opening of the core entrance. Ionic fluxthrough the CNT membrane was monitored using optically absorbing charged marker molecules. Theflux is reduced by a factor of 24 when the desthiobiotin on the CNT is coordinated with streptavidin;release of streptavidin increases the flux, demonstrating a reversible ion-channel flow. Analysis of solutionsof released streptavidin shows approximately 16 bound streptavidin molecules per CNT tip.