The ability to control SARS-CoV-2, the virus that causes the highly contagious Coronavirus disease 2019 (COVID-19), relies on access to rapid and sensitive technologies that can detect the virus, and differentiate SARS-CoV-2 infections from infections with other viruses. Diagnosis of COVID-19 remains largely based on reverse transcription PCR (RT-PCR), which identifies the genetic material of the virus.
Yet, the impact of RT-PCR is hindered by slow delivery of results, with rapid testing based on enzyme-linked immunosorbent assays (ELISA) and lateral flow assays (LFA) technology often preferred as pre-screening methods with results available in 10-20 min. However, these approaches remain challenging due to the limited sensitivity of these sensing platforms. With a cycle threshold (Ct) cut off correlating to Ct = 28 in the best cases, concerns regarding the high frequency of false negative results raised research efforts in finding alternative strategies to real-time RT-PCR tests. One potential approach to detect SARS-CoV-2 is to use sensors comprised of specialized surfaces and chemicals that can detect changes in the properties of samples containing the virus.
The objective of CorDial-S was to bridge this gap though the development of a rapid (<15 min), sensitive (2000 viral particles per mL), selective, and inexpensive solution to address this medical need. The development of a point-of care testing device (POCT) based on the combination of different technologies for the screening of the presence/absence of the SARS-CoV-2 virus in nasal samples was targeted. It includes the use of COVID-19 specific nanobodies, their integrating into an optical sensing cartridge, the use of a portable sensing device and the incorporation of artificial intelligence elements. The project aimed in addition product optimization, and performance validation in a clinical setting, to enable completion of its technical file, and aim for declaration of conformity and affixing of CE mark. The integration of magnetic nanoparticles with high magnetic strength and modified with nanobodies for virus capture was aimed at in addition and proved to be of high complexity.