Voltammetric determination of catechol based on a glassy carbon electrode modified with a composite consisting of graphene oxide and polymelamine

The authors describe an voltammetric catechol (CC) assay based on the use of a glassy carbon electrode (GCE) modified with a composite consisting of graphene oxide and polymelamine (GO/PM). The modified GCE was characterized by field emission scanning electron microscopy, elemental analysis, Raman spectroscopy and FTIR. Cyclic voltammetry reveals a well-defined response to CC, with an oxidation peak current that is distinctly enhanced compared to electrodes modified with GO or PM only. The combined synergetic activity of GO and PM in the composite also results in a lower oxidation potential. Differential pulse voltammetry (DPV) shows a response that is linear in the 0.03 to 138 mu M CC concentration range. The detection limit is 8 nM, and the sensitivity is 0.537 mu Aai...mu M(-1)ai...cm(-2). The sensor is selective for CC even in the presence of potentially interfering compounds including hydroquinone, resorcinol and dopamine. The modified GCE is highly reproducible, stable, sensitive, and shows an excellent practicability for detection of CC in water samples.