In this paper, a non-enzymatic hydrogen peroxide (H 2 O 2) sensor, based on Au nanoparticles (AuNPs) electrodeposited on an electrochemically reduced graphene oxide(ER-GO)-Nafion modified glass carbon electrode (GCE), was reported. The graphene oxide-(GO-)Nafion nanocomposites were first assembled on the GCE surface to produce a GO-Nafion electrode. GO was then electrochemically reduced to produce an ERGO-Nafion modified GCE (to be subsequently denoted as GCE/ERGO-Nafion). Afterwards, AuNPs were electrodeposited on the modified GCE to form a GCE/ERGO-Nafion/AuNPs electrode. The ERGO-Nafion nanocomposites and the electrodeposited AuNPs were characterized by infrared spectroscopy and scanning electron microscopy (SEM). The results showed that the GO was reduced successfully and the AuNPs were uniformly dispersed on the GCE/ERGO-Nafion electrode with a size of about 48nm. The cyclic voltammograms and the amperometric method were used to evaluate the electrocatalytic properties of the GCE/ERGO-Nafion/AuNPs electrode. The results showed that the modified electrode displayed good electrocatalytic activity in relation to the reduction of H 2 O 2 with a detection limit of 2 μM of (H 2 O 2) based on a signal-to-noise ratio of three. The sensor also indicated great sensitivity (574.8 μA/(mM cm 2)), wide linear range (0.02-23 mM), good selectivity and reproducibility, and long-term stability.

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Using supramolecular recognition capability of cucurbit[7]uril to create a novel electrochemical sensing platform was accomplished by self-assembly of cucurbit[7]uril on the surface of graphene-gold composites modified glassy carbon electrode. The graphene-gold composites consisted of electrochemically reduced graphene oxide-nafion matrix and anchored electrodeposited gold nanoparticles and the graphene-gold composites modified glassy carbon electrode (labelled as graphene-gold) were characterized by scanning electron microscopy and Raman spectrometer. Self-assembly of cucurbit[7]uril was achieved by immersing the graphene-gold electrode into cucurbit[7]uril solution and confirmed by Fourier transform infrared spectra, cyclic voltammetry and electrochemical impedance spectroscopy. Ferrocene and its derivatives served as the substrates, and the electrochemical responses of fabricated graphene-gold/cucurbit[7]uril electrode were evaluated. The results showed that the presence of cucurbit[7]uril increased the peak current, improved the reversibility of reaction and extended the recognition ability of the modified electrode.