Facile synthesis of graphene hybrid tube-like structure for simultaneous detection of ascorbic acid, dopamine, uric acid and tryptophan

In the present work, a tube-like structure of graphene hybrid as modifier to fabricate electrode for simultaneous detection of ascorbic acid (AA), dopamine (DA), uric acid (UA) and tryptophan (Trp) was reported. The hybrid was synthesized by a simple method based on graphene sheets (GS) and 3,4,9,10-perylenetetracarboxylic acid (PTCA) via pi-pi stacking interaction under ultrasonic condition. The combination of GS and PICA could effectively improve the dispersion of GS, owing to PTCA with the carboxylic-functionalized interface. Comparing with pure GS or PTCA modified electrode, CS-PICA displayed high catalytic activity and selectivity toward the oxidation of AA, DA, UA. and Trp. Moreover, cyclic voltammetry, different pulse voltammetry and scanning electron microscopy were employed to characterize the sensors. The experiment results showed that the linear response range for simultaneous detection of AA, DA, UA, and Trp were 20-420 mu M, 0.40-374 mu M, 4-544 mu M and 0.40-138 mu M, respectively, and the detection limits were 5.60 mu M. 0.13 mu M, 0.92 mu M and 0.06 mu M (S/N = 3). Importantly, the proposed method offers promise for simple, rapid, selective and cost-effective analysis of small biomolecules. (C) 201 2 Elsevier B.V. All rights reserved.