Development of a real-time biosensing system of SARS-CoV-2 to improve healthcare workers safety during COVID 19 pandemics

Recent results demonstrated an increased risk of COVID-19 infection among healthcare workers (HCW), particularly when access to personal protective equipment (PPE) was inadequate. During the COVID-19 pandemic, access to PPE has become complicated by a surge in worldwide demand combined with production limitations and logistical barriers. Since their introduction in hospitals in the 1990s, filtering facepiece (FFP) masks, mostly of the FFP2 type, are used by HCWs to protect themselves against bioaerosols due to tuberculosis, measles and selected respiratory viruses. The COVID-19 pandemic due to the novel SARS-CoV-2 has sparked debate around judicious and safe use of face masks for the protection of HCWs who provide direct care for COVID-19 patients. At the heart of the discussion is the question whether SARS-CoV-2 is transmitted by droplets or aerosols, or by both. While the former are large (>5µm) and fall rapidly to the ground, the latter are small (<5µm) and can stay in the air and travel much farther than the 1-2 metres normally considered a safe distance to infected patients. Today, we have little information on physical spread and infectious dose of SARS-CoV-2, and the discussion about the choice of face masks is based on indirect data. The starting hypothesis of this project is that decision-making regarding mask-wearing for HCW in the current situation of inadequate mask supply, coupled with uncertainty regarding airborne COVID-19 transmission, can be improved if direct detection of SARS-CoV-2 in aerosols can be implemented in clinical situations where aerosolisation is expected. This would be achieved by installing biosensors. Currently, the reverse transcription polymerase chain reaction (RT-PCR) technology is the most sensitive method for SARS-CoV-2 detection in respiratory secretions and it is routinely used to diagnose COVID-19. A reliable biosensing system that can detect SARS-CoV-2 rapidly, quantitatively and in real-time, supplementing RT-PCR technology would significantly help to understand SARS-CoV-2 transmission and inform recommendations for safe and practical use of PPE, and particularly face masks. In this project, we will validate a novel dual-functional, localized surface plasmon resonance (LSPR) biosensor to improve detection and on-line monitoring of SARS-CoV-2 in clinical settings. The two-dimensional gold nano-islands (AuNIs), functionalized with complementary DNA, can perform sensitive detection of selected sequences from SARS-CoV-2 through nucleic acid hybridization. For better sensing performance, the plasmonic photothermal effect, generated by the same AuNIs chip, and an additional laser irradiance can elevate the local temperature and facilitate the specific discrimination of two similar gene sequences. We aim to integrate a bioaerosol sampling system with a specific biosensor, to allow continuous real-time monitoring the shedding of SARS-CoV-2 virus in droplets or aerosols, aiming to rapidly and continuously collect airborne virus with a high collection efficiency and stable microbial recovery. The collected virus can be efficiently enriched in the sampling liquid and subsequently introduced into the integrated micro-system for virus lysis and nucleic acid extraction. This system is to be tested in clinical situations and with real COVID-19 patients with the aim to understand transmission of SARS-CoV-2 in patient surroundings. In parallel, a cluster-randomised, controlled, cross-over study will evaluate the benefits of wearing surgical masks vs. FFP2 masks during COVID-19 patient care (outside aerosol-generating procedures). To date, no study has combined virus detection technology with a cluster-randomised trial to address the question of appropriate face mask usage in COVID-19 care.