Gold Nanocluster–Molybdenum Disulfide Nanosheet Couple-Based Immunoassay Probe for the Selective Detection of Glial Fibrillary Acidic Protein (GFAP)─A Biomarker for Ischemic Stroke

Stroke, an incapacitating cerebrovascular catastrophe, imposes significant socio-economic burdens by affecting individuals, families, and society at large. Ischemic stroke (IS) particularly disrupts the cerebral blood flow, causing vascular compromise and neurological impairment. The present study introduces a fluorescence immunoassay platform for detecting glial fibrillary acidic protein (GFAP), a critical marker responsive to IS. Employing molybdenum disulfide nanosheet (MoS2 NS) as a quencher upon GFAP antibody-conjugated bovine serum albumin-capped fluorescent gold nanoclusters (MoS2@Ab@AuNCs), the developed assay demonstrates robust detection capabilities. The platform exhibits a linear detection range from 31.15 to 447.76 pg/mL with a detection limit of 1.30 pg/mL. Selectivity and sensitivity assessments against coexisting biomolecules and ions validate the reliability of the probe. Furthermore, feasibility studies using real serum samples confirm its applicability in clinical settings. Additionally, a paper strip-based, cost-effective platform is introduced for rapid GFAP detection, facilitating broader accessibility and utility.