Layer-by-layer films comprised of alternating graphene and gold nanoparticle layers are readily produced by the two-step procedure involving the use of vacuum filtration of a reduced graphene oxide solution to fabricate the graphene thin film on the quartz substrate, followed by gold nanoparticle formation by spontaneous reduction of gold ions in a gold salt solution on the graphene films.

Capacitive photocurrent spectroscopy is used to probe the electronic states of grapheneoxide, and reduced graphene-oxide. Three peaks are observed whose intensities scale with the oxygen coverage. The energy of these peaks correlate with the luminescence spectra reported for graphene-oxide. Using a fitting procedure, the density of states for graphene oxide is extracted from the data. It consis...

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a simple and fast technique for the analysis of large biomolecules but is not suitable for the detection of low molecular weight molecules and compounds, such as flavonoids and phenylpropanoids, mainly due to the lack of an appropriate matrix. Flavonoids and phenylpropanoids, such as coumarin and its ...

The electrochemical reduction of highly oxidized unsupported graphene oxide nanosheets and its platinum electrodeposition was done by the rotating disk slurry electrode technique. Avoiding the use of a solid electrode, graphene oxide was electrochemically reduced in a slurry solution with a scalable process without the use of a reducing agent. Graphene oxide nanosheets were synthesized from car...

This paper reports our findings on how to prepare a graphene oxide-based gas sensor for sensing fast pulses of volatile organic compounds with a better signal-to-noise ratio. We use rapid acetone pulses of varying concentrations to test the sensors. First, we compare the effect of graphene oxide deposition method (dielectrophoresis versus solvent evaporation) on the sensor's response. We find t...

This work aims the functionalization of reduced graphene oxide nanoplatelets with chitosan (G-chitosan) and also with poly(styrenesulfonic acid) (GPSS), thus forming stable, dispersed aqueous solutions. G-chitosan and GPSS solutions allowed the layer-by-layer (LbL) film formation with glucose oxidase (GOx), establishing multilayered nanostructures with elevated control in thickness and morpholo...

An in situ chemical synthesis approach has been developed to prepare ruthenium oxide/reduced graphene oxide (RGO) nanocomposites. It is found that as the C/O ratio increases, the number density of RuO2 nanoparticles decreases, because the chemical interaction between the Ru ions and the oxygen-containing functional groups provides anchoring sites where the nucleation of particles takes place. F...

Graphene and its derivatives combine a numerous range of supreme properties that can be useful in many applications. The purpose of this review is to analyse the photoelectrochemical properties of pristine graphene, graphene oxide (GO) and reduced graphene oxide (rGO) and their impact on semiconductor catalysts/quantum dots. The mechanism that this group of materials follows to improve their pe...

Oxidation of graphite produces graphite oxide, which is dispersible in water as individual platelets. After deposition onto Si/SiO2 substrates, chemical reduction produces graphene sheets. Electrical conductivity measurements indicate a 10000-fold increase in conductivity after chemical reduction to graphene. Tapping mode atomic force microscopy measurements show one to two layer graphene steps...