Electrochemical Vertical Flow Immunoassay for Fast and Decentralized Determination of Stroke-Related Biomarker Glial Fibrillary Acidic Protein.

Rapid identification of stroke types remains a major clinical challenge, as current diagnostic methods often rely on neuroimaging, which is time-consuming and not always accessible in pre-hospital settings or remote zones. Glial fibrillary acidic protein (GFAP) has emerged as a promising biomarker for distinguishing hemorrhagic from ischemic stroke, paving the way for rapid, quantitative, and portable detection platforms. Here, we report an electrochemical vertical flow immunoassay (eVFIA) as a point-of-care device for the on-site determination of GFAP. The device combines a multilayer paper-based architecture with a screen-printed electrochemical cell, enabling rapid vertical flow immunoassay and electrochemical signal generation within 10 min. Through systematic optimization of assay parameters, the eVFIA offered a detection limit of 85 pg/mL and strong agreement with standard ELISA measurements. The vertical flow format accelerates fluid transport, while the electrochemical readout ensures quantitative, light-independent measurements. This platform thus offers a cost-effective and user-friendly approach to determine biomarkers for stroke type differentiation. Although further large-scale validation is needed, the GFAP-eVFIA demonstrates strong potential for deployment in decentralized healthcare environments, providing clinicians with a rapid and reliable tool for early stroke assessment.