Citation: Wasfi, A.;Awwad, F.; Gelovani, J.G.; Qamhieh, N.; Ayesh, A.I. COVID-19 Detection via Silicon Nanowire Field-Effect Transistor: Setup and Modeling of Its Function. Nanomaterials 2022, 12, 2638. https://doi.org/10.3390/ nano12152638 Academic Editor: Simone Morais Received: 2 June 2022 Accepted: 18 July 2022 Published: 31 July 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). nanomaterials Article COVID-19 Detection via Silicon Nanowire Field-Effect Transistor: Setup and Modeling of Its Function Asma Wasfi 1,2 , Falah Awwad 1,2, *, Juri George Gelovani 3 , Naser Qamhieh 4 and Ahmad I. Ayesh 5 1 Department of Electrical Engineering, College of Engineering, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates; 201180954@uaeu.ac.ae 2 Zayed Center for Health Sciences, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates 3 College of Medicine and Health Sciences, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates; jgelovani@uaeu.ac.ae 4 Department of Physics, College of Science, United Arab Emirates University, Al Ain P.O. Box 15551, United Arab Emirates; nqamhieh@uaeu.ac.ae 5 Physics Program, Department of Mathematics, Statistics and Physics, College of Arts and Science, Qatar University, Doha P.O. Box 2713, Qatar; ayesh@qu.edu.qa * Correspondence: f_awwad@uaeu.ac.ae Abstract: Biomolecular detection methods have evolved from simple chemical processes to laboratory sensors capable of acquiring accurate measurements of various biological components. Recently, silicon nanowire field-effect transistors (SiNW-FETs) have been drawing enormous interest due to their potential in the biomolecular sensing field. SiNW-FETs exhibit capabilities such as providing real-time, label-free, highly selective, and sensitive detection. It is highly critical to diagnose infectious diseases accurately to reduce the illness and death spread rate. In this work, a novel SiNW-FET sensor is designed using a semiempirical approach, and the electronic transport properties are studied to detect the COVID-19 spike protein. Various electronic transport properties such as transmission spectrum, conductance, and electronic current are investigated by a semiempirical modeling that is combined with a nonequilibrium Green’s function. Moreover, the developed sensor selectivity is tested by studying the electronic transport properties for other viruses including influenza, rotavirus, and HIV. The results indicate that SiNW-FET can be utilized for accurate COVID-19 identification with high sensitivity and selectivity. Keywords: COVID-19; FET biosensor; semiempirical modeling 1. Introduction For the last twenty years, various nanomaterials including nanogaps, nanotubes, nanowires, nanoparticles, and nanoscale films [1–6] have attracted researchers’ interest due to their potential for designing nanoscale sensors. Various nanoscale sensing methods have been utilized in biological applications and research. Precise and rapid detection mecha- nisms are required to monitor living systems. The major factors in designing and fabricating the biomolecular sensors are a low cost, quick and accurate results, and high sensitivity and selectivity. Field-effect transistors (FETs) have potential in sensor applications due to their ability to translate the molecule’s interaction with the sensor to readable signals in real time [7–9]. Recently, various semiconducting materials types such as nanowires [10,11] and carbon materials [12,13] have shown promise in the fabrication of field-effect transistor- based sensors. Carbon-based sensors have been developed for different applications such as glucose concentration detection [14], DNA hybridization [15,16], antigen–antibody in- teractions [10,17,18], and cancer biomarkers detection [19,20]. Despite the advantages of carbon-based sensors such as carbon nanotube (CNT) FETs in biomolecular applications, several limitations were identified in the fabrications processes and applications as well. The fabrication of CNT-FETs with both metallic and semiconducting elements still requires Nanomaterials 2022, 12, 2638. https://doi.org/10.3390/nano12152638 https://www.mdpi.com/journal/nanomaterials