ABSTRACT
The rise in antibiotic-resistant pathogens, highly infectious viruses, and chronic diseases has prompted the search for rapid and versatile medical tests that can be performed by the patient. An electronic biosensing platform based on field-effect transistors (FETs) is particularly attractive due to sensitivity, fast turn-around, and compatibility with semiconductor manufacturing. However, the lack of methods for pathogen-specific functionalization of individual FETs prevents parallel detection of multiple pathogens. Indeed, so far functionalization of FET based biosensors is achieved by drop casting without any spatial selectivity. Here, we propose a paradigm shift in FET’s biofunctionalization. Specifically, we use thermal scanning probe lithography (tSPL) with a thermochemically sensitive polymer that can be spin-coated on any FET material. We demonstrate that this scalable, CMOS compatible methodology can be used to functionalize individual FETs with different bioreceptors on the same chip, at sub-20 nm resolution, paving the way for massively parallel FET detection of multiple pathogens. Antibody- and aptamer-modified FET sensors are then realized, achieving an ultra-sensitive detection of 5 aM of SARS-CoV-2 spike proteins and 10 human SARS-CoV-2 infectious live virus particles/ml, and selectivity against human influenza A (H1N1) live virus.
Subject(s)
Severe Acute Respiratory Syndrome , Chronic DiseaseABSTRACT
Ozone is a powerful anti-bacterial, anti-fungal and anti-viral agent, yet exposure to high levels of ozone can pose risks to human/animal health and, in the long term, corrode certain objects. In order to overcome these risks, we evaluated the potential of using a relatively short exposure of a low concentration of ozone to disinfect an indoor environment in the absence of individuals and animals. ICON3 by O3ZONO/M2L, a new disinfection device generating both ozone and negative ions, was selected to assess the potential of this strategy to inactivate different viral isolates of SARS-CoV-2. Tests under controlled laboratory conditions were performed in a system consisting of an ozone-proof airtight plastic box inside a biological safety cabinet, where suspensions of two strains of SARS-CoV-2 were exposed to ozone and negative ions and virucidal activity was measured by means of two complementary methodologies: viral replication capacity and viral titer determination. These studies revealed that low concentration ozone (average 3 ppm after the peak) inactivated up to >99% of SARS-CoV-2 within 20 minutes of exposure. Under controlled conditions, similar ozone exposure was recreated with ICON3 in different volume rooms (15, 30, 60 m3) where a linear relationship was observed between the room volume and the time of continuous ozone/ions flow required to reach and maintain the desired ozone levels used in the laboratory studies. These studies suggest that ICON3 may have the potential for use in the disinfection of SARS-CoV-2 in indoor environments in the absence of individuals and animals, under properly controlled and monitored safety conditions.