A Novel Sensitive Electrochemical Sensor for the Simultaneous Determination of Hydroquinone and Catechol using Tryptophan-Functionalized Graphene

A novel tryptophan-functionalized graphene nanocomposite was employed for the simultaneous determination of hydroquinone and catechol. The analyte electrochemical behavior on the surface of tryptophan-functionalized graphene was investigated by cyclic voltammetry and differential pulse voltammetry. Compared to conventional graphene, enhanced peak currents were obtained that were attributed to the large number of defects on tryptophan-functionalized graphene that accelerated electron transfer between the electrode and analytes. The peak potential difference between hydroquinone and catechol at the tryptophan-functionalized graphene modified glassy carbon electrode was 104 millivolt, which was sufficiently wide to simultaneously determine hydroquinone and catechol. This method was used for the analysis of tap water.