ABSTRACT
Continued advances in label-free electrical biosensors pave the way to simple, rapid, cost-effective, high-sensitivity, and quantitative biomarker testing at the point-of-care setting that would profoundly transform healthcare. However, implementation in routine diagnostics is faced with significant challenges associated with the inherent requirement for biofluid sample processing before and during testing. We present here a simple yet robust autonomous finger-prick blood sample processing platform integrated with nanoscale field-effect transistor biosensors and demonstrate the feasibility of measuring the SARS-CoV-2 nucleocapsid protein. The 3D-printed platform incorporates a high-yield blood-to-plasma separation module and a delay valve designed to terminate the assay at a specific time. The platform is driven by hydrostatic pressure to efficiently and automatically dispense plasma and washing/measurement buffer to the nanosensors. Our model study demonstrates the feasibility of detecting down to 1.4 pg/mL of the SARS-CoV-2 nucleocapsid protein within 25 min and with only minimal operator intervention.