Label-Free Detection of Plant Pathogens Using a Dielectric- and Charge-Density-Modulated Vertical Ferroelectric TFET Pathogen Sensor with Leaf Extract

Abstract A label-free pathogen sensor based on a stacked-source ferroelectric p–n–i–n vertical tunnel field-effect transistor (TFET) is proposed for high-sensitivity plant pathogen detection using leaf extract. The sensing mechanism synergistically combines dielectric modulation, described through the Bruggeman effective-medium framework, and interface charge modulation to perturb the tunneling barrier and electrostatic potential. The incorporation of a ferroelectric layer enables internal voltage amplification via the negative capacitance effect, significantly enhancing band-to-band tunneling efficiency. The device achieves an ultra-high drain-current sensitivity on the order of ∼107 in the subthreshold regime, along with distinct threshold voltage shifts (∼0.1–0.25 V) for different classes of plant pathogens. The proposed architecture exhibits strong linearity (R2 ≈ 0.97) and maintains stable response under coupled temperature and humidity variations. These results highlight the potential of the proposed TFET pathogen sensor as a robust, low-power platform for rapid electrical modulation and field-oriented plant pathogen detection.