Application of poly(acridine orange) and graphene modified carbon/ionic liquid paste electrode for the sensitive electrochemical detection of rutin

A carbon/ionic liquid paste electrode (CILPE) prepared by 1-hexylpyridinium hexafluorophosphate as the binder was used as the substrate electrode. A layer of graphene oxide (GO) film was cast on CILPE surface (GO/CILPE) and the electropolymerization of acridine orange (AO) on electrode was further realized by cyclic voltammetry in the potential range from −1.40 V to 1.40 V, which could simultaneously reduce GO to graphene (GR) electrochemically. The fabricated PAO-GR/CILPE exhibited good electrochemical performances with higher conductivity and lower electron transfer resistance. Electrochemical behaviors of rutin were further investigated on the modified electrode in 0.1 mol/L pH 2.0 phosphate buffer solution by cyclic voltammetry with a pair of well-defined redox peaks appeared. The peak-to-peak separation (ΔEp) was calculated as 0.076 V, which proved a fast quasi-reversible electron transfer process and the electrochemical parameters of rutin on PAO-GR/CILPE were calculated. Under the optimal conditions, the linear relationship between the oxidation peak current of rutin and its concentration was obtained in the range from 0.03 to 800.0 μmol/L with the detection limit as 8.33 nmol/L (3σ). The PAO-GR/CILPE showed good selectivity, stability and reproducibility, which was further applied to detect rutin tablet samples with satisfactory results.