Amperometric determination of H2O2 based on Prussian blue @ palladium nanoparticles/graphene oxide nanocomposite modified electrode

Hydrogen peroxide (H2O2), a hazardous chemical, is known to be developing severe health issues, widely used in various fields, involved in several biological events and intracellular pathways and is the by-product of oxidase enzyme-based catalyzed reactions. Therefore, it is very important to develop rapid, simple, sensitive, inexpensive, reliable, and accurate H2O2 detection sensors. Up to date, various analytical methods have been used for the accurate and sensitive determination of H2O2 [1-5]. Among these methods, electrochemical techniques have received extensive interest compared with the existing traditional methods. Nonenzymatic H2O2 sensors based on nanoscale materials have attracted much attention due to their unique characteristics, such as high sensitivity, large specific surface area, low detection limit, wide respond range and chemical stability [6]. To date, plenty of nanomaterials have been used to achieve a better sensitivity and selectivity in the enzyme-free H2O2 sensors [5, 7, 8]. Transition metal hexacyanoferrates (Mhcf) have achieved significant interest due to their important properties such as magnetism, electrochromism displays, electrocatalysts, and applications in sensor design and batteries. Prussian blue (PB) has been described as ‘‘artificial peroxidase’’ for H2O2 electrocatalysis. However, rapid desorption of PB film from electrode surface is the main problem that resulted in losing its catalytic activity. In order to overcome this problem, researches focused on developing methods for the synthesis of nanostructured PB objects and their deposition onto various conductive materials, such as carbon nanotube, graphene, bulk metal substrates and other substrates [9, 10]. The performance of the composite materials relies on the properties of the individual components, and on the effective structural combination of the components [11]. Here, we fabricated a new triple-component non-enzymatic sensor by sequential deposition of Pd and PB nanoparticles on GO modified PGE for the determination of 321 H2O2. To create close contact between PB and GO we have electrodeposited Pd on GO modified PGE and used this electrode for the chemically deposition of PB because noble metals are actively promote the growth of PB. The resulting sensor combines the advantages of GO, Pd and PB nanoparticles and show good sensitivity and excellent electrocatalytic ability. This modified electrode was characterized by several techniques including scanning electron microscopy (SEM), energy dispersive X–ray spectroscopy (EDX), and cyclic voltammetry (CV). The sensor showed significantly better electrocatalytic activity for the reduction of hydrogen peroxide in comparison with the single GO/PGE, PB/GO/PGE and Pd/Go/PGE modified electrodes. This was attributed to the synergistic effect of PB, Pd and GO nanoparticles. Also, this proposed sensor demonstrated an overall high level of performance for the analysis of H2O2 using hydrodynamic amperometry in the concentration range from 0.2 μM to 0.5 mM and detection limit of 0.049 μM with good stability, repeatability, and selectivity.