A Hydrogen Peroxide Biosensor Based on the Immobilization of the Highly Stable Royal Palm Tree Peroxidase (Roystonea regia) with Chitosan and Glutaraldehyde on Screen-printed Graphene Electrodes

This paper present the fabrication and electrochemical stud-ies of a screen-printed graphene electrode (SPGE) modified with Roy-al palm tree peroxidase (RPTP) in combination with chitosan (CS) and cross-linking of glutaraldehyde (GA) for detection of hydrogen perox-ide. Cyclic voltammograms in the presence of potassium ferrocyanide ([Fe(CN)6]3-/4-) as a redox species demonstrated an increasing of 50mA evidenced by the electron transfer process of SPGE modified with CS-GA-RPTP. The graphene modified electrode exhibits excellent electrocatalytic activity to the reduction of H2O2, with a linear response in the 100 mM to 5 mM concentration range and a detection limit of 87 mM. The new sensor based on the modification of graphene electrode with the high stable RPTP will provide a potential amperometric detection system for determination of H2O2 in real samples with some biomedical or environmental importance.