Recent progress in nanomaterial-based electrochemical biosensors for hydrogen peroxide detection & their biological applications

The electrochemical biosensor has brought a paradigm shift in the field of sensing due to its fast response and easy operability. The performance of electrochemical sensors can be modified by coupling them with various metal oxides, nanomaterials, and nanocomposites. Hydrogen peroxide is a short-lived reactive oxygen species that plays a crucial role in various physiological and biological processes. Therefore, its monitoring is of paramount importance. With this, the research fraternity has developed various nanomaterial-based superlative sensors that have enhanced the sensing performance towards H₂O₂ in terms of sensitivity, detection limit, and linear range. The integration of nanocomposite materials has allowed for the synergistic combination of different components, leading to improved sensor stability, selectivity, and detection limits. The precious metal alloys, metal oxides, semiconductor nanomaterials, carbon cloth, multi-walled carbon nanotubes, graphene oxide, and nanoparticles demonstrate effective catalytic performance for detecting H₂O₂ electrochemically. These advanced materials possess extraordinary properties and structures, rendering them highly advantageous for diverse applications. These biosensors aid in monitoring H₂O₂ levels secreted by MCF-7, HeLa cells, NIH-3T3, and A549 cells in real-time. Further, this type of biosensor identified alterations in H₂O₂ levels in the lungs, bronchoalveolar lavage fluid (BALF) of mice with pulmonary fibrosis, activated hepatic stellate cells, and the livers of mice with liver fibrosis. The current review highlights the recent advancements in compositions, morphology, limit of detection, sensitivity, biological applications, etc. properties of the electrochemical biosensors for H₂O₂ detection.