Simultaneous determination of hydroquinone and catechol using a modified glassy carbon electrode by ruthenium red/carbon nanotube

Abstract

A decorated glassy carbon (GC) electrode with functionalized multi-walled carbon nanotube (CNTs) and ruthenium red (RR) has been used for simultaneous determination of hydroquinone (HQ) and catechol (CC). The electrocatalytic behaviors of the GC/CNTs–RR were studied in acetate buffer solution with pH 4.5 by differential pulse voltammetry and chronoamperometry techniques. Due to the excellent electrocatalytic activity and enhanced electrical conductivity of the CNTs–RR, the simultaneous determination of HQ and CC with two well-defined peaks was achieved at the GC/CNTs–RR modified electrode. The catalytic peak currents linearly depend on the HQ and CC concentrations in the range of 1.3–433.3 µM with the sensitivity of 5.0 µA µM−1 cm−2 and 7.45 µA µM−1 cm−2, respectively. The detection limits for HQ and CC were obtained 0.21 and 0.18 µM. The diffusion coefficient for the oxidation of HQ and CC at the modified electrode was calculated as 1.06 ± 0.05 × 10−6 and 1.76 ± 0.07 × 10−5 cm2 s−1, respectively. The proposed sensor was successfully examined for real water samples analysis and revealed stable and reliable recovery data.