Meander-gated dual cap GaN HEMT-based portable noninvasive COVID-19 detection platform

In this Letter, an epitaxial and device design has been proposed for the noninvasive detection of COVID-19 using a portable hand-held system. A ∼1.5-fold enhancement in sensitivity was observed for the meander-gated biosensor as compared to the conventional design. The sensitivity was further enhanced by ∼1.70 times when a dual cap layer was used instead of a conventional epitaxial design. A peak sensitivity of 252.70 μA/pg/ml with good linearity was observed for IL-6 detection in hyposmia. Thus, the importance of biosensor epitaxial and device design has been demonstrated. Saliva-based noninvasive detection of IL-6 in COVID-19 offers a sensitivity of 22.96 μA/pg/ml. The biosensing platform has a shelf-life of around 4 weeks with a minute change of ∼1.26% in sensitivity, fast detection (<10 s), limit of detection of 0.24 fg/ml, and a linear dynamic range of 0.1–80.0 pg/ml. The proposed biosensing platform has the potential for early detection, prognosis, and management of COVID-19 in point-of-care application areas.