Noncovalent Interactions of Molecules with Single Walled Carbon Nanotubes

Biomolecular detections performed on carbon nanotube field-effect transistors (CNT-FETs) frequently use reactive pyrenes as an anchor to tether bioactive ligands to the hydrophobic nanotubes. In this paper, we explore the possibility of directly using bioactive aromatic compounds themselves as CNT-FET ligands. This would be an efficient way to functionalize CNT-FETs since many aromatic compounds bind avidly to nanotubes, and it would also ensure that ligand-binding molecules would be brought in close proximity to the nanotubes. Using a model system consisting of pyrene, phenanthrene, naphthalene, or phenyl boronic acids immobilized on CNT-FET wafers, we show that all are able to bind glycated human serum albumin (gHSA), which is an important diabetes marker. Pyrene boronic acid proved to bind CNTs with the greatest apparent affinity as measured by gHSA impedance. Interestingly, gHSA CNT-FET signal intensity, which is proportional to amount of protein bound, remained essentially unchanged for all the boronic acids tested.

Section: Introductionmentioning

confidence: 99%

Evaluation of Aromatic Boronic Acids as Ligands for Measuring Diabetes Markers on Carbon Nanotube Field-Effect Transistors

Stefansson¹,

Stefansson²,

Chung³

et al. 2012

“…Over the past 20 years, research efforts have aimed to improve both efficiency and selectivity of nanotube synthesis, as well as understand their chemical reactivity and extraordinary electronic and thermal properties [3][4][5]. Carbon nanotubes have significant potential for application in molecular electronics [6][7][8][9][10][11][12][13][14][15], nanomechanics [16][17][18][19][20], optics [21][22][23][24], sensors [6,[25][26][27][28][29][30][31], and even catalysis [32].…”

Section: Introductionmentioning

confidence: 99%

Theoretical Studies of Substitutionally Doped Single-Walled Nanotubes

Yeung

Chen

Wang

2010

The rich chemistry of single-walled carbon nanotubes (SWCNTs) is enhanced by substitutional doping, a process in which a single atom of the nanotube sidewall is replaced by a heteroatom. These so-called heteroatom-substituted SWCNTs (HSWCNTs) exhibit unique chemical and physical properties not observed in their corresponding undoped congeners. Herein, we present theoretical studies of both main group element and transition metal-doped HSWCNTs. Within density functional theory (DFT), we discuss mechanistic details of their proposed synthesis from vacancy-defected SWCNTs and describe their geometric and electronic properties. Additionally, we propose applications for these nanomaterials in nanosensing, nanoelectronics, and nanocatalysis.

“…Chen et al [29] reported that small molecule with rich conjugated π electrons such as pyrene derivatives could be bound onto the surface of carbon nanotubes through noncovalent π-π interactions. Moreover, there are some reports where functional groups could be bounded directly on the surface of carbon nanotubes through covalent or noncovalent methods [13][14][15][16][17][18][19][29][30][31][32][33][34][35][36]. Subsequently, Zanella et al [37] developed a simple direct solvent-free procedure to anchor the gold nanoparticles on the surface of MWNTs functionalized with aliphatic dithiols and aminothiols.…”

Section: Introductionmentioning

confidence: 99%

Noncovalent Interaction between Gold Nanoparticles and Multiwalled Carbon Nanotubes via an Intermediatory

Yeh

Huang

Lin

et al. 2009

A new and effective method has been developed where self-assembled gold nanoparticles (Au-NPs) of ∼10 nm diameter are successfully attached onto the surface of sidewalls and ends of thiol-terminated multi-walled carbon nanotubes (MWNTs) functionalized with orthomercaptoaniline, acting as a bridging agent. It can bridge the carbon nanotubes (CNTs) and Au-NPs via the bi-functional moiety with benzene unit at one end and thiol group at the other end by self-assembly. The ortho-mercaptoaniline was first grafted onto the surface of the CNTs via π-π interaction between the benzene ring of the mercaptoaniline and π-conjugated body of MWNTs surface to produce thiol-terminated CNTs. The bare surface of Au-NPs facilitates to attach on the thiol group of the thiol-terminated CNTs. Attenuated total reflectance FTIR, UV-visible, Raman spectroscopy and X-ray powder diffraction studies were used to verify whether the mercapto-benzene moieties have been attached to the π-conjugated body of functionalized MWNTs. The direct evidence is obtained from transmission electron microscope (TEM) images where selfassembled Au-NPs are attached onto the functionalized MWNTs.