High-Sensitivity Detection of Infectious Disease via Fe ₃ O ₄ @UiO-66-NH ₂ Combined with a Graphene Field-Effect Transistor

Infectious diseases remain a serious global health threat due to their high transmissibility and mortality, highlighting the urgent need for sensitive and rapid diagnostic tools to enable early detection and effective intervention. Herein, we report an ultrasensitive biosensing platform that integrates Fe₃O₄@UiO-66-NH₂ nanocomposites with a graphene field-effect transistor (GFET) for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The nanocomposites were conjugated with antibodies against SARS-CoV-2, enabling selective capture of viral particles from complex biological matrices. Following magnetic enrichment, the GFET sensor was employed for signal transduction and quantitative analysis. The platform demonstrated a broad dynamic range (1 ag·mL^-1 to 10 ng·mL^-1) with an exceptionally low detection limit of 1.98 ag·mL^-1. Furthermore, successful detection of SARS-CoV-2 antigens in serum samples highlights its potential for point-of-care and real-time diagnostic.