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

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.