Desarrollo de un prototipo de biosensor basado en peroxidasa de palma real (Roystonea regia) y nanotubos de péptidos inmovilizados sobre electrodos de oro para detección de peróxido de hidrógeno

In this work we developed a novel H₂O₂ enzymatic biosensor through the co-immobilization of royal palm tree peroxidase (RPTP) (Roystonea regia) with peptide nanotubes (PNTs) on screen-printed gold electrodes employing glutaraldehyde as a cross-linking agent. The biosensor development begins with the isolation and purification of peroxidase from the leaves of palm tree. Then the surface of the electrode was modified by adsorption of the conjugate RPTP-PNT and the electrochemical characterization was made by cyclic voltammetry (CV) and chronoamperometry techniques. The CVs exhibited a redox potential around -0.4 V using an Ag/AgCl reference electrode. The enzymatic biosensor shows a catalytic response towards different hydrogen peroxide concentrations. Analytical parameters such as: linear range, sensibility and detection limit exhibited values of 500-6000 μM, 0.022 μA L/mol and 432 μM, respectively. A surface-controlled process electron transfer was observed and the biosensor exhibited a pH dependence. The novel biosensor presented in this work could be a potential bioanalytical tool for the detection of hydrogen peroxide in real samples of biomedical and environmental importance.