Electrochemical fabrication of polyproline modified graphite electrode decorated with Pd-Au bimetallic nanoparticles: Application for determination of carminic acid

A novel modified electrode has been developed, by electrodeposition of Pd-Au bimetallic nanoparticles (Pd-AuNps) on a polypyroline coated (Poly(Pr)) graphite electrode (GE). The structure and morphologies of Pd-AuNps/Poly(Pr)/GE were characterized by cyclic voltammetry (CV), square wave voltammetry (SWV), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray photon spectroscopy (XPS) techniques. The electrocatalytic activities and morphologies of the new electrode were compared with individual monometallic AuNps/PoIy(Pr)/GE and PdNps/Poly(Pr)/GE. This new bimetallic nanoparticle modified electrode (Pd-AuNps/Poly(Pr)/GE) was evaluated for determination of carminic acid. The oxidation peak (0.750 V) of carminic acid was found to be linearly related to carminic acid concentration in the range of 1.0 x 10(-8) to 1.0 x 10(-6) M with a detection limit of 5.90 x 10(-9) M. The proposed method was simple, less time consuming and showed a high sensitivity. (C) 2015 Elsevier B.V. All rights reserved.