Microwave-Assisted Synthesis of a Core–Shell MWCNT/GONR Heterostructure for the Electrochemical Detection of Ascorbic Acid, Dopamine, and Uric Acid

Abstract

In this study, graphene oxide nanoribbons (GONRs) were synthesized from the facile unzipping of multiwalled carbon nanotubes (MWCNTs) with the help of microwave energy. A core-shell MWCNT/GONR-modified glassy carbon (MWCNT/GONR/GC) electrode was used to electrochemically detect ascorbic acid (AA), dopamine (DA), and uric acid (UA). In cyclic voltammograms, the MWCNT/GONR/GC electrode was found to outperform the MWCNT- and graphene-modified GC electrodes in terms of peak current. For the simultaneous sensing of three analytes, well-separated voltammetric peaks were obtained using a MWCNT/GONR/GC electrode in differential pulse voltammetry measurements. The corresponding peak separations were 229.9 mV (AA to DA), 126.7 mV (DA to UA), and 356.6 mV (AA to UA). This excellent electrochemical performance can be attributed to the unique electronic structure of MWCNTs/GONRs: a high density of unoccupied electronic states above the Fermi level and enriched oxygen-based functionality at the edge of the graphene-like structures, as revealed by X-ray absorption near-edge structure spectroscopy, obtained using scanning transmission X-ray microscopy.

Remarkably High Heterogeneous Electron Transfer Activity of Carbon-Nanotube-Supported Reduced Graphene Oxide

“…[1][2] Heterogeneous electron transfer (HET) at solid electrodes, including graphene, is the subject of many theoretical and methodological studies in electrochemistry. 3 Enhancement of the HET activity of graphene materials is key to realizing their potential applications in myriad important areas such as energy storage/conversion, [4][5][6] molecular sensing, [7][8] and electrocatalysis. [9][10][11] Moreover, there is growing interest in developing a deeper understanding of the fundamental electron transfer behavior of graphene materials, particularly the HET kinetics.…”

Electrochemical behavior of hybrid carbon nanomaterials: the chemistry behind electrochemistry

“…The synergistic effects of the MWCNT and the GONR result in an improved electrochemistry, as shown in the detection of ascorbic acid, uric acid and dopamine [22], p-dihydroxybenzene [23], polycyclic aromatic amines [24] or in biosensing [25].…”

Nanocarbon-based electrochemical systems for sensing, electrocatalysis, and energy storage

“…[229] For electrocatalysis applications, the 32 doping of CNTs and graphene with heteroatoms to modulate their electronic structures and charge distributions 33 proved to be the key to improved catalytic activities. [132] For supercapacitor applications, band structure engineer-…”

“…Sun et al [229] reported microwave-assisted synthesis of a core-shell MWCNT/graphene oxide 4 nanoribbon (GONRs) heterostructure (Figure 8a, 8c-8e). CV measurements (Figure 8b) show that GONR/GC 5 exhibits a much higher current density than does GC, MWCNT/GC, or graphene/GC.…”

“…Reprinted with permission from ref [67] . Reprinted with permission from ref [229] . Reprinted with permission from ref [132] .…”