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Neurological disorders such as epilepsy arise from disrupted brain networks. Our capacity to treat these disorders is limited by our inability to map these networks at sufficient temporal and spatial scales to target interventions. Current best techniques either sample broad areas at low temporal resolution (e.g. calcium imaging) or record from discrete regions at high temporal resolution (e.g. electrophysiology). This limitation hampers our ability to understand and intervene in aberrations of network dynamics. Here we present a technique to map the onset and spatiotemporal spread of acute epileptic seizures in vivo by simultaneously recording high bandwidth microelectrocorticography and calcium fluorescence using transparent graphene microelectrode arrays. We integrate dynamic data features from both modalities using non-negative matrix factorization to identify sequential spatiotemporal patterns of seizure onset and evolution, revealing how the temporal progression of ictal electrophysiology is linked to the spatial evolution of the recruited seizure core. This integrated analysis of multimodal data reveals otherwise hidden state transitions in the spatial and temporal progression of acute seizures. The techniques demonstrated here may enable future targeted therapeutic interventions and novel spatially embedded models of local circuit dynamics during seizure onset and evolution.

Biosensors based on graphene field effect transistors (GFETs) decorated with antibody‐functionalized platinum nanoparticles (PtNPs) are developed for the quantitative detection of breast cancer biomarker HER3. High‐quality chemical vapor deposited graphene is prepared and transferred over gold electrodes microfabricated on an SiO₂/Si wafer to yield an array of 52 GFET devices. The GFETs are modified with PtNPs to obtain a hybrid nanostructure suitable for attachment of HER3‐specific, genetically engineered thiol‐containing single‐chain variable fragment antibodies (scFv) to realize a biosensor for HER3. Physical and electrical characterization of Bio‐GFET devices is carried out by electron microscopy, atomic force microscopy, Raman spectroscopy, and current–gate voltage measurements. A concentration‐dependent response of the biosensor to HER3 antigen is found in the range 300 fg mL⁻¹to 300 ng mL⁻¹and is in quantitative agreement with a model based on the Hill–Langmuir equation of equilibrium thermodynamics. Based on the dose–response data, the dissociation constant is estimated to be 800 pg mL⁻¹, indicating that the high affinity of the scFv antibody is maintained after immobilization. The limit of detection is 300 fg mL⁻¹, showing the potential for PtNP/G‐FETs to be used in label‐free biological sensors.