Fast and real-time electrical transistor assay for quantifying SARS-CoV-2 neutralizing antibodies

Due to the SARS-CoV-2 pandemic renewed attention has been directed towards viral neutralization assays and neutralizing antibodies quantification, for vaccine pre-clinical trials and determining vaccine efficacy over time. The gold standard to assess antibody titer is the plaque reduction neutralization test, an end-point assay which evaluates the highest serum antibody dilution that neutralizes viral replication, by inspecting the cytopathic effect induced on cell cultures. Here, we use planar, PEDOT:PSS-based organic electrochemical transistors for real-time, remote-controlled, reliable and fast electrical monitoring of the cytopathic effect induced by SARS29 CoV-2 on Vero E6 cell lines, allowing the quantification of serum neutralizing titer. Our low-cost and scalable device has the potential to speed-up large-scale viral neutralization screening without the need for cancerous staining or highly specialized operators. Finally, the technology could be easily transferred to assess neutralizing antibody response towards different viruses in their permissive cell substrates.