Amperometric determination of hydroquinone and catechol on gold electrode modified by direct electrodeposition of poly(3,4-ethylenedioxythiophene)

Poly(3,4-ethylenedioxythiophene) (PEDOT) was directly deposited onto a gold electrode through potentiostatic technology, and the PEDOT modified electrode was developed for the amperometric determination of hydroquinone and catechol in 0.1 M phosphate buffer solution (pH 7.0). Compared with the bare electrode, both hydroquinone and catechol exhibited well-defined redox peaks and much larger peak currents at PEDOT modified gold electrode, which suggested the higher specific surface area and conductivity of the PEDOT film. Under the optimized condition, the amperometric current response on PEDOT modified electrode were linear over ranges from 1.0 × 10−7 M to 4.9 × 10−5 M for hydroquinone, and from 9.1 × 10−8 M to 9.8 × 10−4 M for catechol, with the detection limits of 1.2 × 10−8 M and 0.9 × 10−8 M, respectively. The proposed method was applied on the determination of the mixture of hydroquinone and catechol with satisfactory results.