Electrodeposited Prussian Blue on carbon black modified disposable electrodes for direct enzyme-free H2O2 sensing in a Parkinson’s disease model

Reactive Oxygen Species (ROS) are reduced forms of oxygen such as superoxide anion, hydroxyl radical or hydrogen peroxide. These molecules have a critical role in physiological processes like cellular signalling, immunological activity. However, an overproduction may cause the so-called oxidative stress (OS) which is able to cause damage to lipids, proteins or DNA. These alterations promote pathophysiological conditions such as diabetes, cancer, Alzheimer’s and Parkinson’s disease. Carbon Black (CB) is a carbon nanomaterial widely used as reinforcing material and as filler in the preparation of rubber and plastic compounds and composites. CB dispersions after sonication, in appropriate solvents, appears as carbon nanoparticles. The ‘nano CB’ exhibit excellent conductivity, unique electrochemical properties and cost-effectiveness (about 1 euro/kg). For these reasons, in the last years several works have been reported on the CB dispersion for electrode modification. In this work, we present the combination of Carbon Black (CB) and electrodeposited Prussian Blue (PB) covered with a Nafion layer on Screen-Printed electrodes (CB/PB-SPE) used for non-enzymatic H2O2 sensing in Neuroblastoma cell line SH-SY5Y. These cells were challenged with 6-hidroxidopamine (6-OHDA) for modelling Parkinson’s disease. The electrodes surface was investigated using Scanning Electron Microscopy (SEM) and electrochemically characterized, in terms of electroactivity and stability. Electrochemical sensing of H2O2 was carried out at very low potentials (-50mV), allowing interference-free detection of H2O2 in the selected cell culture. The H2O2 concentration was successfully monitored in an experimental model of Parkinson’s disease. These results pave the way to a method for the continuous monitoring of H2O2 in culture medium for future studies of the role of H2O2 in Parkinson’s disease