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 (k(s)) and the charge transfer coefficient () have been calculated as 6.08 s(-1) and 0.74 respectively. This sensor showed a wide linear response for Rtn from 7.0x10(-8) to 7.0x10(-6) M and 7.0x10(-6) to 1.0x10(-4) M with a limit of detection (2.05 +/- 0.04)x10(-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.