Electrochemical determination of ascorbic acid, dopamine and uric acid based on an exfoliated graphite paper electrode: A high performance flexible sensor

• A flexible electrochemical sensor is successfully constructed by using a consumer-grade flexible graphite paper.
• The exfoliated flexible graphite paper electrode with rough edges possesses high electrocatalytic activity toward the oxidation of ascorbic acid, dopamine and uric acid.
• The flexible sensor with merits of high selectivity and low detection limits has great potential applications in flexible electronics.

An exfoliated flexible graphite paper (e-FGP) with rough edges is proposed as a high performance working electrode for the electrochemical determination of ascorbic acid (AA), dopamine (DA), and uric acid (UA). Scanning electron microscopy (SEM), cyclic voltammetry (CV), different pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) were applied to investigate the unique properties of the high performance electrode. The results demonstrate its excellent electrocatalytic activity toward the oxidation of AA, DA and UA with well-separated voltammetric peaks. The calibration curves in the range of 20–400 μM, 0.5–35 μM, 0.5–35 μM, and the detection limits (S/N = 3) of 2.0 μM, 0.01 μM, 0.02 μM were obtained for AA, DA and UA in neutral phosphate buffer solutions (PBS), respectively. This mechanically flexible sensor with good selectivity and remarkable sensitivity could be used to determine DA and UA in real human urine samples.