Clinical validation of SARS-CoV-2 electrochemical immunosensor based on the spike-ACE2 complex

Background and aims: Advances in health, especially in prevention, diagnosis, and treatment, have significantly impacted the way of facing emerging infectious diseases. Yet, events such as the COVID-19 pandemic have shown that there is still a long way to go. Therefore, an urgent need exists for portable and easily deployable point-ofcare (POC) detection tools. Biosensors at the POC remain in the laboratory in an analytical characterization step and are not yet mature enough to reach the market massively. In this context, it is necessary to progress in validating these devices to demonstrate their relevance in detecting different disease biomarkers. This work reports on the clinical validation of an electrochemical immunosensor for detecting SARS-CoV-2. Methods: A monocentric retrospective cohort study was conducted with 150 random nasopharyngeal swabs or tracheal aspiration samples tested by RT-PCR. The immunosensor based on magnetic beads and chronoamperometry detected SARS-CoV-2 through the spike-angiotensin-converting protein (ACE2) immunocomplex. Results: This biosensor demonstrated 96.04 % clinical sensitivity and 87.75 % clinical specificity in detecting SARS-CoV-2 in the samples, highly correlated with the RT-PCR gold standard. Conclusions: It demonstrates the potential of electrochemical biosensors to be implemented as highly sensitive and easily deployable detection strategies even in remote locations.