Dextran complexes with single-walled carbon nanotubes

Stobiński, Leszek; Polaczek, Elzbieta; Rębilas, Krzysztof; Mazurkiewicz, Józef; Wrzalik, R.; Lin, Hong-Ming; Tomasik, Piotr

doi:10.14314/polimery.2008.571

Cited by 9 publications

(7 citation statements)

References 1 publication

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“…The binding between SWCNT and dextran is limited solely to its hydrophobic interaction with the central part of the dextran chain. Dextran‐SWCNT complexes have been previously made by the traditional method of adding solid SWCNT to aqueous dextran as we mentioned above . However, our method requires the addition of methanol that causes dextran precipitation and thereby no recovery of Dextran‐SWCNT.…”

Section: Resultsmentioning

confidence: 99%

A Ratiometric Sensor Using Single Chirality Near‐Infrared Fluorescent Carbon Nanotubes: Application to In Vivo Monitoring

Giraldo

Landry

Kwak³

et al. 2015

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166

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Advances in the separation and functionalization of single walled carbon nanotubes (SWCNT) by their electronic type have enabled the development of ratiometric fluorescent SWCNT sensors for the first time. Herein, single chirality SWCNT are independently functionalized to recognize either nitric oxide (NO), hydrogen peroxide (H2O2), or no analyte (remaining invariant) to create optical sensor responses from the ratio of distinct emission peaks. This ratiometric approach provides a measure of analyte concentration, invariant to the absolute intensity emitted from the sensors and hence, more stable to external noise and detection geometry. Two distinct ratiometric sensors are demonstrated: one version for H2O2, the other for NO, each using 7,6 emission, and each containing an invariant 6,5 emission wavelength. To functionalize these sensors from SWCNT isolated from the gel separation technique, a method for rapid and efficient coating exchange of single chirality sodium dodecyl sulfate‐SWCNT is introduced. As a proof of concept, spatial and temporal patterns of the ratio sensor response to H2O2 and, separately, NO, are monitored in leaves of living plants in real time. This ratiometric optical sensing platform can enable the detection of trace analytes in complex environments such as strongly scattering media and biological tissues.

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Section: Resultsmentioning

confidence: 99%

A Ratiometric Sensor Using Single Chirality Near‐Infrared Fluorescent Carbon Nanotubes: Application to In Vivo Monitoring

Giraldo

Landry

Kwak³

et al. 2015

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162

166

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“…13 30-33 The cationic 20 In our case, the hydroxyl groups attract a thin layer of water in close proximity to the SWCNT outer side-wall. CTAB does not dissolved in NMP.…”

Section: Resultsmentioning

confidence: 83%

The Removal of Metallic Single-Walled Carbon Nanotubes Using an Aqueous Two-Phase System

Tang¹,

Whitcher²,

Yeoh³

et al. 2014

j. nanosci. nanotech.

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Here we report our findings on the removal of metallic single-walled carbon nanotubes using an aqueous two-phase system. The aqueous two-phase system contained as received carbon nanotubes, polyethylene glycol, dextran, N-methylpyrrolidone, cetyltrimethylammonium bromide, and water which phase separated into top and bottom phases. The top phase was dominated by polyethylene glycol whereas the bottom phase was dominated by dextran. The dextran-rich phase contained more semiconducting species while metallic species was more abundant in the polyethylene glycol rich-phase. It was found via Fourier-Transform Infrared Spectroscopy that cetyltrimethylammonium bromide only present in the dextran-rich phase. A selectivity mechanism is tentatively proposed and discussed.

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“…A mixture of SDS and SC was also tested to compare how much the surface coverage parameter changes compared to the pure surfactants. The second group consists of polystyrenesulfonate (PS), of which molecular weights are 70 000 g/mol (PS 70k) and 200 000g/mol (PS 200k), chitosan, and dextran. , Discussion of PS corona phases with different molecular weights addresses the polymer length as one of parameters affecting the surface coverage of SWNT corona phase. The ssDNA group includes (GT) 15 , (AT) 15 , and (GTTT) 7 , which are well-known to hybridize on the surface of SWNTs .…”

Section: Resultsmentioning

confidence: 99%

Measuring the Accessible Surface Area within the Nanoparticle Corona Using Molecular Probe Adsorption

et al. 2019

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The corona phase-the adsorbed layer of polymer, surfactant or stabilizer molecules around a nanoparticle-is typically utilized to disperse nanoparticles into a solution or solid phase. However, this phase also controls molecular access to the nanoparticle surface, a property important for catalytic activity and sensor applications. Unfortunately, few methods can directly probe the structure of this corona phase, which is subcategorized as either a hard, immobile corona or a soft, transient corona in exchange with components in the bulk solution. In this work, we introduce a Molecular Probe Adsorption (MPA) method for measuring the accessible nanoparticle surface area using a titration of a quenchable fluorescent molecule. For example, riboflavin is utilized to measure the surface area of gold nanoparticle standards, as well as corona phases on dispersed single walled carbon nanotubes and graphene sheets. A material balance on the titration yields certain surface coverage parameters, including the ratio of the surface area to dissociation constant of the fluorophore, q K D as well as K D itself. Uncertainty, precision, and the correlation of these parameters across different experimental systems, preparations, and modalities are all discussed. Using MPA across a series of corona phases, we find that the Gibbs free energy of probe binding scales inversely with the cube root of surface area, q. In this way, MPA is the only technique to date capable of discerning critical structure-property relationships for such nanoparticle surface phases. Hence, MPA is a rapid quantitative technique that should prove useful for elucidating corona structure for nanoparticles across different systems.

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Dextran complexes with single-walled carbon nanotubes

Cited by 9 publications

References 1 publication

A Ratiometric Sensor Using Single Chirality Near‐Infrared Fluorescent Carbon Nanotubes: Application to In Vivo Monitoring

A Ratiometric Sensor Using Single Chirality Near‐Infrared Fluorescent Carbon Nanotubes: Application to In Vivo Monitoring

The Removal of Metallic Single-Walled Carbon Nanotubes Using an Aqueous Two-Phase System

Measuring the Accessible Surface Area within the Nanoparticle Corona Using Molecular Probe Adsorption

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