Electrode modifications using nanostructured materials for the determination of hydroquinone

Carbon nanotubes (CNT) and gold nanospheres (AuNS) are nanostructured materials (NSM) that have been widely used to modify electrode surfaces because they in creased the sensitivity of electrochemical sensors[1].In the present work the effect of different MNE, such as multiwalledcarbon nanotubes without functionalization (CNT) and functionalized with carboxylic acids and amine groups (CNT-COOH and CNT-NH2 respectively), and gold nanospheres in the oxidation of hydroquinone (HQ)to quinone (Q) was studied using electrochemical techniques. A 3-electrode cell was used, using an NSM-modifiedglassy carbon electrode, an Ag/AgCl reference electrode and a platinum coil as a counter electrode.When a modified electrode was used with the different nanotubes, the capacitive current and the redox process current (HQ / Q) increased, being greater whenboth, CNT-COOH and CNT-NH2were used (Fig.1). The presence of AuNS increased the current response for the redox process, obtaining higher currents for the GC / CNT-NH2-AuNS modification (Fig. 2). Finally, this electrode was used for the simultaneous determination of the HQ in the presence of its structural isomers catechol and resorcinol, achieving well defined and separated peaks.