Mass testing is fundamental to face the pandemic caused by the coronavirus SARS-CoV-2 discovered at the end of 2019. To this aim, it is necessary to establish reliable, fast, and cheap tools to detect viral particles in biological material so to identify the people capable of spreading the infection. We demonstrate that a colorimetric biosensor based on gold nanoparticle (AuNP) interaction induced by SARS-CoV-2 lends itself as an outstanding tool for detecting viral particles in nasal and throat swabs. The extinction spectrum of a colloidal solution of multiple viral-target gold nanoparticles—AuNPs functionalized with antibodies targeting three surface proteins of SARS-CoV-2 (spike, envelope, and membrane)—is red-shifted in few minutes when mixed with a solution containing the viral particle. The optical density of the mixed solution measured at 560 nm was compared to the threshold cycle ( C t ) of a real-time PCR (gold standard for detecting the presence of viruses) finding that the colorimetric method is able to detect very low viral load with a detection limit approaching that of the real-time PCR. Since the method is sensitive to the infecting viral particle rather than to its RNA, the achievements reported here open a new perspective not only in the context of the current and possible future pandemics, but also in microbiology, as the biosensor proves itself to be a powerful though simple tool for measuring the viral particle concentration.
【저자키워드】 SARS-CoV-2, antibody, Gold nanoparticles, colorimetric biosensors, photochemical immobilization technique, point-of-care device, 【초록키워드】 viruses, pandemic, Infection, nasal, coronavirus SARS-CoV-2, RNA, Real-time PCR, Viral load, Pandemics, optical, threshold, Gold nanoparticle, Interaction, Detection limit, Concentration, throat swabs, mass, gold standard, Perspective, viral particle, surface protein, AuNP, infecting, identify, detect, caused, reported, 【제목키워드】 Test, detection, Throat,