Nonenzymatic uric acid electrochemical sensor based on graphene-modified carbon fiber electrode

A facile and cost effective approach has been developed towards electrochemical fabrication of graphene-modified carbon fiber electrode (GE/CFE) to determine the content of uric acid (UA) via cyclic voltammetry (CV) and potentiostatic (i–t) methods. The combined merits of GE and CFE endow the electrode with large specific surface area and high electrical conductivity. The advantage of thus obtained GE/CFE for UA detection is supported by its higher peak current intensity and lower oxidation potential compared with those of bare glassy carbon electrode (GCE), bare carbon fiber electrode (CFE), and graphene-modified glassy carbon electrode (GE/GCE). Further amperometric study gives a wide liner range from 0.194 μM to 49.68 μM and a low detection limit of 0.132 μM (S/N = 3) with fast response time for the determination of UA on GE/CFE. The determination of UA with GE/CFE is highly selective and reproducible, within a relative standard deviation of 2.8%.