An interdigitated graphene-based platform for ex situ analysis of radiation-induced oxidative stress in astrocyte...

Radiotherapy remains a primary treatment for brain cancers but induces neuronal damage through the generation of reactive oxygen species (ROS), particularly hydrogen peroxide (H₂O₂). Astrocytes, which provide essential neuroprotective support, are highly sensitive to oxidative stress. Thus, monitoring H₂O₂ dynamics in these cells is critical for understanding radiation-induced neurotoxicity. Conventional fluorescence-based ROS probes, such as DCFH-DA and optogenetic sensors, face limitations in selectivity, signal stability, and multiplexing. To address these challenges, we developed an electrochemical sensing platform for real-time monitoring of H₂O₂ in astrocyte cultures. The system employs laser-scribed graphene (LSG) interdigitated electrodes with platinum (Pt) and Prussian blue (PB) functioning as generator and collector electrodes, respectively. PB's molecular selectivity toward H₂O₂ enables high specificity and mitigates interference from electroactive species in complex media. The sensor exhibited a limit of detection of 4.58 μM and a sensitivity of 579 mA M^-1·cm^-2 in cell culture medium. Its capability was validated by detecting extracellular H₂O₂ released from X-ray-irradiated astrocytes across varying doses and time points. Overall, this graphene-based electrochemical system provides a robust and scalable approach for real-time analysis of radiation-induced oxidative stress, offering a valuable tool for studying neuroprotection, radiotherapy response, and brain-on-chip disease modeling.