Detection of H2O2 Using Redox Active Nanoparticles Immobilized on Highly Ordered Polymer Nanopillars

Hydrogen peroxide is a toxic byproduct of respiration arising from the catalytic breakdown of superoxide radicals in our body. Biologically derived H₂O₂ is considered to be an indicator of oxidative stress related diseases such as cancer, parkinson's disease and alzheimer's. Additionally, high concentration of H₂O₂ used in industries and disinfecting agent’s poses a serious environmental issue. The direct or indirect detection of residual H₂O₂ is one of the main issues in the design and fabrication of sensors. Cerium oxide nanoparticles (CNPs) are versatile nano-constructs that have the potential to act as antioxidant that can scavenge H₂O₂, attributed to its switching of oxidation state from +3 to +4 mediated at the oxygen vacancies. CNPs are tested in in vivo and in vitro milieu for biotechnology and medicine applications related to excessive oxidative stress. CNPs are used in detecting H₂O₂ by undergoing electrochemical reactions, thereby constituting them in the making of sensors to detect H₂O₂ inside the body or the residual H₂O₂ in the atmosphere. In this study, the same is achieved by forming a stable coating of immobilized CNPs on high aspect ratio nano-pillars made of polymer. The nanofabrication of nanopillars made of biocompatible polymers using soft lithography shall increase the surface area of exposed CNPs, thereby increasing the interaction of the nanoparticles with the analyte (H₂O₂). The efficiency of detection of H₂O₂ is then analyzed using spectroscopy and electrochemical route.