Simultaneous voltammetric determination of dihydroxybenzene isomers at single-walled carbon nanohorn modified glassy carbon electrode

• SWCNH-modified electrode has fine electrocatalytic activity to dihydroxybenzenes.
• It exhibits the increase in peak current and the decrease in peak separation.
• The oxidation peaks of three dihydroxybenzene isomers are well-separated.
• Simultaneous detection of three dihydroxybenzene isomers is achieved.

The voltammetric behaviors of dihydroxybenzene isomers were studied at the single-walled carbon nanohorn modified glassy carbon (SWCNH-modified GC) electrode. Compared with the bare electrode, SWCNH-modified GC electrode has stronger electrocatalytic activity for the oxidation of dihydroxybenzenes with the increase in peak current and the decrease in peak separation (ΔEp) between the anodic and cathodic peaks. Furthermore, the three isomers can be determined simultaneously and sensitively by using linear sweep voltammetry at the SWCNH-modified GC electrode. For hydroquinone, catechol, and resorcinol, the oxidation peak currents are linear with the concentrations in the range of 0.5–100 μM, 0.5–100 μM, and 1.0–100 μM, respectively. Their detection limits at a signal-to-noise ratio of 3 are 0.1 μM, 0.2 μM, and 0.5 μM, respectively. These results make SWCNH-modified GC electrode a promising candidate for the simultaneous determination of isomers.