The goal of VIROMECH is to determine the technical feasibility of the application of nanomechanical spectrometry, i.e., the identification of nanoparticle analytes by their mechanical properties, to the detection with real-time infectivity assessment of airborne viruses. The project aims to provide proof of concept of a technological approach that integrates state of the art viral aerosol sampling technology, based upon aerosol to hydrosol collection, concentration and purification, with the measurement of the mass and stiffness of the collected viruses by nanomechanical flexural beam resonators, where the viruses are adsorbed after being delivered from the collected liquid suspension by electrospray ionization and aerolens focusing. The measurement of mass and stiffness of individual viruses by reading out the frequency shift response of nanomechanical resonators upon virus adsorption will enable their untargeted detection by harnessing the distinctive distribution patterns of these properties, without the need of specific bioreceptors. The radical innovation of exploiting the existing correlations between virus infectivity and stiffness will open an unprecedented approach for virus infectivity assessment in real time, an information not given by the most advanced nucleic-acid detection techniques such as quantitative real-time polymerase chain reaction (qRT-PCR), and without the need of highly time-consuming cell culture assays, which take up to weeks, depending on the virus type, to provide infectivity information. Although the scientific basis of the pursued application has already been studied and it is solidly supported by many scientific research results, including those from the National Project EXOFLUX from which VIROMECH is derived, proof of concept (TRL3) and validation in laboratory conditions (TRL4) have not been achieved. VIROMECH pursues these objectives by focusing on two specific aspects that require demonstration of their technical feasibility: i) the preservation of virus infectivity during analyte transfer from solution to the surface of the nanomechanical sensors, and ii) the simultaneous optimization of mass and stiffness sensing performance of prototype sensing devices for discerning among infectious/non-infectious viruses. Achieving these objectives will derive in two potential products of great interest in the general areas of bioaerosol science and technology and microbiology, such as an instrument capable of efficiently transfer fragile organic/microbiological analytes from solution to any kind of micro/nanodevice with a small sensitive area, and nanomechanical sensors to characterize the mass and stiffness of viruses for the specific application of airborne virus detection. The implementation of the exploitation and intellectual property protection strategies considered in VIROMECH will facilitate to bring those products closer to suitable markets. The advances pursued by the technological application envisioned in VIROMECH will enable the long- term development of on-site deployable systems capable of rapid, unmanned, ultrasensitive detection of infectious airborne viruses relying on low-cost disposable sensors that allow indoor air monitoring for controlling infectious outbreaks, triggering warning alerts at concentration levels and exposure times below the thresholds for host-to-host airborne transmission, minimizing the social and economic effects of future pandemics.
