Novel graphene flowers modified carbon fibers for simultaneous determination of ascorbic acid, dopamine and uric acid

• A novel GEF modified electrode is fabricated and used for detection of AA, DA and UA.
• It shows high selectivity and good responsiveness for determination of AA, DA and UA.
• The GEF/CFE shows satisfactory results when applied in urine and serum samples.

A novel and sensitive carbon fiber electrode (CFE) modified by graphene flowers was prepared and used to simultaneously determine ascorbic acid (AA), dopamine (DA) and uric acid (UA). SEM images showed that beautiful and layer-petal graphene flowers homogeneously bloomed on the surface of CFE. Moreover, sharp and obvious oxidation peaks were found at the obtained electrode when compared with CFE and glassy carbon electrode (GCE) for the oxidation of AA, DA and UA. Also, the linear calibration plots for AA, DA and UA were observed, respectively, in the ranges of 45.4–1489.23 μM, 0.7–45.21 μM and 3.78–183.87 μM in the individual detection of each component. By simultaneously changing the concentrations of AA, DA and UA, their oxidation peaks appeared at −0.05 V, 0.16 V and 2.6 V, and the good linear responses ranges were 73.52–2305.53 μM, 1.36–125.69 μM and 3.98–371.49 μM, respectively. In addition, the obtained electrode showed satisfactory results when applied to the determination of AA, DA and UA in urine and serum samples.