A novel ZnO/reduced graphene oxide and Prussian blue modified carbon paste electrode for the sensitive determination of Rutin

A carbon paste modified sensor based on a novel composite of zinc oxide nanoparticles deposited on reduced graphene oxide (ZnO-rGrO) and Prussian blue (PB) was drop-cast (ZnO-rGrO-PB/MCPE) for the sensitive estimation of Rutin (Rtn) at pH 7.0. The high surface area of ZnO-rGrO and electrocatalytic property of PB promotes the oxidation of Rtn. Field emission scanning electron microscope (FE-SEM) and energy-dispersive X-ray spectroscopy (EDX) techniques were employed to confirm the deposition of ZnO-rGrO and PB on carbon paste electrode (CPE). The ability of ZnO-rGrO-PB/MCPE in charge transfer at the interface was investigated using electrochemical impedance spectroscopy (EIS). The heterogeneous rate constant (ks) and the charge transfer coefficient (α) have been calculated as 6.08 s−1 and 0.74 respectively. This sensor showed a wide linear response for Rtn from 7.0×10−8 to 7.0×10−6 M and 7.0×10−6 to 1.0×10−4 M with a limit of detection (2.05±0.04)×10−8 M (S/N=3). The application of ZnO-rGrO-PB/MCPE was found in the analysis of Rtn in fruit juice samples using standard addition method. This sensor showed good reproducibility, stability, selectivity and sensitivity.