An electrochemical sensing platform based on a reduced graphene oxide–cobalt oxide nanocube@platinum nanocomposite for nitric oxide detection

Abstract

We report a facile one-pot hydrothermal synthesis of reduced graphene oxide-cobalt oxide nanocubes@platinum (rGO-Co 3 O 4 @Pt) nanocomposite and its application toward the electrochemical detection of nitric oxide (NO). The rGO-Co 3 O 4 @Pt nanocomposite was characterized by field emission scanning electron microscopy (FESEM), energy dispersive X-ray (EDX) mapping, X-ray diffraction (XRD) and Raman analyses. The nanocomposite modified glassy carbon (GC) electrode was used for the electrochemical oxidation of nitric oxide (NO) and it showed better catalytic performance in terms of catalytic peak current and shift in overpotential when compared to rGO, Co 3 O 4 nanocubes and rGO-Co 3 O 4 nanocomposite modified electrodes. The rGO-Co 3 O 4 @Pt nanocomposite modified electrode showed a better sensing ability toward the in-situ generated NO in NO 2 containing phosphate buffer solution (PBS) than the other controlled modified electrodes. The Pt nanoparticles present in the nanocomposite could enhance the sensing performance and the limit of detection (LOD) was found as 1.73 µM with signal-to-noise (S/N) ratio ~3 using amperometric i-t curve. Further, the nanocomposite modified electrode showed the selectivity toward the detection of NO in the presence of 100-fold higher concentration of other physiologically important analytes. The proposed sensor was stable, reproducible and selective toward the detection of NO.

Design and Electrochemical Study of Platinum-Based Nanomaterials for Sensitive Detection of Nitric Oxide in Biomedical Applications

“…The limit of detection (LOD) was calculated to be 3.69 nM (S/N of 3). The obtained limit of detection was much lower than that of other electrodes reported in the literature including rGO-Co 3 O 4 @Pt [42], Pt/MWCNT [59], Pt/AB [60] electrodes. The prepared nanocomposite based sensor exhibited a long-term stability and good reproducibility.…”

“…Recently, Huang and co-workers demonstrated the amperometric sensing of NO based on a rGO-cobalt oxide nanocube@platinum (rGO-Co 3 O 4 @Pt) nanocomposite electrode [42]. The rGO-Co 3 O 4 @Pt nanocomposite with efficient dispersion of Pt nanoparticles on the Co 3 O 4 in the rGO sheets was synthesized via a hydrothermal treatment at 180 °C for 12 h with Teflon-lined stainless steel autoclave.…”

“…The developed nanocomposite electrodes exhibited enhanced sensing performance with a low detection limit of 1.7 µM, and showed high stability with good reproducible measurements. The developed rGO-Co 3 O 4 @Pt [42], Pt/MWCNT [59], Pt/AB [60] electrodes exhibited less sensitive than that of the nanopore Pt based electrodes, revealing that the nanopore Pt electrode possessed a high surface area and high catalytic activity toward NO oxidation [45,57]. …”

“…The use of Pt-based nanocomposites in sensors may serve as one effective strategy toward the augmentation of their electronic, chemical, and electrochemical properties [17,36,37,38,39]. Platinum based nanocomposites such as bimetallic Pt-based alloy nanoparticles, Pt nanoparticles dispersed on various substrates such as metal oxides, carbon nanotubes (CNTs), reduced graphene oxide (rGO), and rGO/ionic liquid (IL) composites, may further enhance the oxidation of NO molecules due to their synergistic electronic effects [23,24,40,41,42,43]. Platinum based nanomaterials as sensing electrode materials may be added to the surfaces of electrodes or modified Pt electrodes through numerous strategies, including physical adsorption, chemical covalent bonding, electrochemical reduction, electrochemical deposition, electrochemical polymerization with redox polymers, etc.…”

Water-soluble Hantzsch ester as switch-on fluorescent probe for efficiently detecting nitric oxide

“…In last few decades, various fluorescent compounds and materials, including quantum dots [21], inorganic complexes [22][23][24], nanoparticles [25,26], biomacromolecule or cyclodextrin based fluorophores [27,28] and small organic fluorescent molecules [29], have been well established as valid chemosensors to detect NO in vitro and analyze the NO generation and distribution in cells or living organisms. Among them, small organic molecules particularly attracted attentions because of its intrinsic advantages such as easy preparation, good stability and adjustable structures.…”