Simultaneous determination of hydroquinone and catechol by a reduced graphene oxide-polydopamine-carboxylated multi-walled carbon nanotube nanocomposite.

A reduced graphene oxide-polydopamine-carboxylated multi-walled carbon nanotube (RGO-PDA-cMWCNT) nanocomposite was fabricated a facile, one-pot procedure and was characterized by a variety of techniques. A novel electrochemical sensor based on RGO-PDA-cMWCNT was constructed to determine hydroquinone (HQ) and catechol (CT) simultaneously. This newly prepared nanocomposite shows excellent electrocatalytic efficacy in the electrode reaction of the two isomers. Specifically, the peak-to-peak potential difference between the two dihydroxybenzenes is 115 mV for oxidation, which is obviously larger than similar electrochemical sensors. The established method displays a wide linear range from 0.5 to 5000 μM with a detection limit (S/N = 3) of 0.066 μM for HQ and 0.073 μM for CT. In addition, this electrochemical approach has been tested to measure the two dihydroxybenzenes in real samples and satisfactory results were recorded.