In this work, we havesuccessfully demonstrated an on-chip GFETplatform as a real-time, label-free, and selective tool for the detectionof neurological diseases biomarker GFAP with ultrahigh sensitivity.Our on-chip GFET sensors were able to directly detect GFAP in patientplasma samples with the LOD down to the femtomolar level without signalamplification within minutes. This evidence concerns the gene GFAP and nervous system disorder.