High-performance graphene field-effect transistor platform for on-site schizophrenia-related biomarkers detection

Schizophrenia remains challenging to diagnose objectively, as conventional assessments rely on subjective symptom evaluation and are often associated with significant diagnostic delays. In this study, we present a portable, multiplexed graphene field-effect transistor (GFET) biosensor array for the simultaneous and ultrasensitive detection of three schizophrenia-related biomarkers-cortisol, serotonin, and dopamine-at femtomolar concentrations. Fabricated using microelectromechanical systems processes, the array integrates three monolayer graphene channels on a single chip, each covalently functionalized with a specific bioreceptor to ensure high selectivity and minimal cross-reactivity. Real-time monitoring of transfer characteristics enables detection via Dirac point shifts induced by bioreceptor-analyte binding. The GFET platform demonstrates femtomolar-level sensitivity, broad dynamic range, and specificity in both phosphate-buffered saline and artificial serum. Moreover, the system supports real-time, Bluetooth-enabled data transmission, offering a rapid and objective point-of-care tool to complement conventional psychiatric diagnostics. This platform holds promise for reducing diagnostic latency, supporting personalized treatment strategies, and advancing precision mental health care.