Issue 21, 2010

SPR imaging study of DNA wrapped single wall carbon nanotube (ssDNA-SWCNT) adsorption on a model biological (collagen) substrate

Abstract

The adsorption kinetics of single stranded-DNA dispersed single wall carbon nanotubes (ssDNA-SWCNTs) onto an immobilized collagen layer in a microfluidic channel was probed using surface plasmon resonance imaging (SPRi). The adsorption was measured for a range of both nanotube and solution parameters including the nanotube concentration, nanotube length, solution pH, and the type of medium (buffer and river water). The kinetic adsorption data suggests that the adsorption of the nanotubes to the collagen layer is irreversible in HEPES buffer, pH ≈ 7.4, at room temperature, with the nanotube adsorption displaying two different kinetic adsorption regimes for different concentration ranges. A stretched exponential function fit indicates that a transition of adsorption kinetics from single exponential (>40 μg/mL) to non-exponential kinetics (<40 μg/mL) occurs as the nanotube concentration decreases, suggesting that a diffusion-limited process was predominant at lower concentrations (<40 μg/mL). Adsorption measurements as a function of nanotube length also displayed differences in the apparent adsorption processes. Adsorption of shorter nanotubes (≈ 40 nm) was found to follow single exponential kinetics, while longer nanotubes (≈ 300 nm) adsorbed much more slowly, consistent with adsorption partially influenced by diffusion-limited processes. Finally, to evaluate the potential differences in adsorption for unintentionally released nanotubes in a riparian environment, nanotubes were stably dispersed in a sample of river water and exposed to the collagen layer. Compared to the adsorption under HEPES buffer the nanotubes in the river water were found to exhibit a reduced rate of adsorption. It is likely that passivation of the collagen layer by dissolved organic species could thus affect the fate of released nanotubes in a natural environment.

Graphical abstract: SPR imaging study of DNA wrapped single wall carbon nanotube (ssDNA-SWCNT) adsorption on a model biological (collagen) substrate

Article information

Article type
Paper
Submitted
11 May 2010
Accepted
12 Aug 2010
First published
20 Sep 2010

Soft Matter, 2010,6, 5581-5588

SPR imaging study of DNA wrapped single wall carbon nanotube (ssDNA-SWCNT) adsorption on a model biological (collagen) substrate

J. J. Park, J. A. Fagan, J. Y. Huh, K. B. Migler, A. Karim and D. Raghavan, Soft Matter, 2010, 6, 5581 DOI: 10.1039/C0SM00368A

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements