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

Stroke,\nan incapacitating cerebrovascular catastrophe, imposes\nsignificant socio-economic burdens by affecting individuals, families,\nand society at large. Ischemic stroke (IS) particularly disrupts the\ncerebral blood flow, causing vascular compromise and neurological\nimpairment. The present study introduces a fluorescence immunoassay\nplatform for detecting glial fibrillary acidic protein (GFAP), a critical\nmarker responsive to IS. Employing molybdenum disulfide nanosheet\n(MoS<sub>2</sub> NS) as a quencher upon GFAP antibody-conjugated bovine\nserum albumin-capped fluorescent gold nanoclusters (MoS<sub>2</sub>@Ab@AuNCs), the developed assay demonstrates robust detection capabilities.\nThe platform exhibits a linear detection range from 31.15 to 447.76\npg/mL with a detection limit of 1.30 pg/mL. Selectivity and sensitivity\nassessments against coexisting biomolecules and ions validate the\nreliability of the probe. Furthermore, feasibility studies using real\nserum samples confirm its applicability in clinical settings. Additionally,\na paper strip-based, cost-effective platform is introduced for rapid\nGFAP detection, facilitating broader accessibility and utility.