Following the outbreak of the SARS-CoV-2 pandemic, the demand for faster diagnostic systems has pushed research activities towards the development of innovative technologies for the detection of the virus through simple, fast and low-cost methods. However, the current diagnostic procedure relies on the molecular technique of Reverse Transcription Polymerase Chain Reaction (RT-PCR), which is expensive and time-consuming.
Aiming at addressing this issue, a plasmonic biochemical sensor for SARS-CoV-2 was realized by combining a plasmonic plastic optical D-shaped fiber sensor with a brand-new kind of synthetic molecularly imprinted polymer (MIP) receptor. The synthetic MIP was properly designed for the molecular recognition of the Subunit 1 of the SARS-CoV-2 Spike protein.
Preliminary experimental results on the developed sensor were performed to test its effectiveness in binding the Subunit 1 of the SARS-CoV-2 Spike protein in different solutions. Afterwards, tests on the SARS-CoV-2 virions were carried on using nasopharyngeal (NP) swabs in UTM (universal transport medium) and physiological solution (0.9% NaCl). The results achieved were compared in the end with those obtained with RT-PCR.
According to these results, the proposed optical biochemical sensor proved to effectively determine SARS-CoV-2 virions in biological samples and with an even higher sensitivity than the RT-PCR one. Furthermore, a reasonably quick response time to the virus (about 10 minutes) was achieved.