This article describes the fabrication of a glassy
carbon electrode (GCE) modified with a film containing
graphene and gold nanoparticles (AuNPs) that can be used
for the determination of nitric oxide (NO) at pH 7.0. A layer of
gold nanoparticles was first deposited on the GCE, this
followed by coating it with a film of graphene and Nafion.
The response of the electrode to NO was studied by cyclic
voltammetry and amperometry. A sharp anodic peak was
observed at 0.81 V, and the anodic peak current was largely
increased compared to a bare GCE or a mono-film modified
GCE. A negative shift of the anodic peak potential (by
220 mV) indicates that the composite film has a beneficial
effect on ease of the electrochemical oxidation of NO. The
electron t r ansfer number was calculated from
chronocoulometric data. The amperometric response to NO
is linear in the 36 nM to 20 μM concentration range (with a
correlation coefficient of 0.9981), and the detection limit is
18 nM (at a S/N of 3). The release of NO from the fish liver
homogenate stimulated by L-arginine was studied with this
electrode.