Early detection of COVID-19 is crucial for pandemic control, necessitating the development of accurate, rapid, portable, and point-of-care testing devices. In this paper, we present a novel system comprising a carbon nanotube fi eld-eff ect transistor (swCNT-FET) biosensor functionalized with SARS-CoV-2 nucleocapsid protein antibody (Ab-NP), an IoT-based portable reader, and data analysis software for real-time COVID-19 detection. The Ab-NP functionalized swCNT-FET designed to transduce the biological binding event between COVID-NP and Ab-NP into an electrical signal. A microcontroller-based portable reader, designed to meet the biosensor’s signal acquisition specifi cations, was implemented. The suggested system, incorporates Ab-NP/swCNT-FET, IoT-based portable reader, and data processing software, was successful detection of COVID-NP at fM concentrations, highlighting its potential for clinical applications.