Probing Biomolecular Interactions with Gold Nanoparticle-Decorated Single-Walled Carbon Nanotubes

Abstract

Hybrid nanomaterials comprising metal−graphitic interfaces are uniquely suitable to probe molecular interactions and the associated phenomena such as charge transfer and adsorbate spillover effects. Herein, we study the modulation of the electronic and chemical properties of gold nanoparticle-decorated single-walled carbon nanotubes (SWCNT) using Raman spectroscopy and measurements of field-effect transistor (FET) characteristics. SWCNT are extremely sensitive to changes in the local electronic environment and therefore gold-analyte interactions may be probed both through changes in FET characteristics (as an electrical transducer) and in surface-enhanced Raman scattering (as a chromophore). We study these changes both experimentally and theoretically in order to elucidate the electronic structure of complex nanocomposites, and the information gathered from these experiments is applied to the study of biomolecular interactions with gold nanoparticle-decorated SWCNT. This study, in addition to providing deeper understanding of metal− graphitic interfaces, will offer a combined approach to SWCNT biosensing methodology based on the dual monitoring of the FET−Raman characteristics, which we demonstrate through detection of glutathione.

Addressing the Theoretical and Experimental Aspects of Low-Dimensional-Materials-Based FET Immunosensors: A Review

“…Michael et al [115] also presented a density functional theory (DFT) study to confirm the charge transfer hypothesis mentioned above. Figure 3c shows pictorial views of the corresponding charge difference maps performed for GSSG and GSH molecules.…”

“…Michael et al [115] presented an interesting study on the modulation of the electronic properties of FET devices based on SWCNTs decorated with gold nanoparticles (Au NPs) in the presence of the common stress biomarkers, reduced glutathione (GSH), and oxidized glutathione (GSSG). For this purpose, the authors used milder oxidized (ox) SWCNTs to electrodeposit the Au NPs on its surface.…”

“…In the work of Michael et al [115], both GSH and GSSG are adsorbed on Au NPs through the formation of Au-S bonds. The transfer characteristics of the proposed device show a decrease in the FET conductance as the concentration of GSH (Figure 3b(i)) and GSSG (Figure 3b(ii)) is increased.…”

Gold-carbonaceous materials based heterostructures for gas sensing applications

“…The rigid superstructure nanowires obtained can be changed in morphology by changing the concentration of precursor material. Recently, Michael et al 137 reported the theoretical and experimental aspects of the electronic interactions between graphitic and Au NPs interface. The enhanced Raman signals obtained due to Surface-Enhanced Raman Scattering (SERS) on the graphitic interface with plasmonic nanoparticles.…”

Recent Advances in Characterization Techniques for the Interface in Carbon Nanotube-Reinforced Polymer Nanocomposites

“…Since the discovery of carbon nanotubes and, in particular, the realization of their unique performance [1][2][3][4], much effort has been devoted to develop advanced nanocomposites with carbon nanotubes as reinforcement [5][6][7][8][9][10]. Full understanding of the excellent behavior of carbon nanotubereinforced nanocomposites requires knowledge of the interactions at the interface between the carbon nanotubes and the matrix [11][12][13][14][15][16]. ere are no essential differences between such a requirement and that for conventional fiber-reinforced composites, but the characteristic length scale of the reinforcement varies from micrometer to nanometer.…”