Rapid and direct quantification of the SARS-CoV-2 virus with an ultrasensitive nanobody-based photonic nanosensor

Abstract

The coronavirus (CoV) disease 2019 (COVID-19) is expected to become endemic in the upcoming years, meaning that the worldwide society shall be prepared to routinely manage the highly contagious respiratory...

Biomimetic nanoplasmonic sensor for rapid evaluation of neutralizing SARS-CoV-2 monoclonal antibodies as antiviral therapy

“…The SARS-CoV-2 viruses were produced and provided by the National Institute of Infectious Diseases (INMI) of Rome (Italy), and they were duly inactivated through ultraviolet (UV) irradiation (15 min, λ 254 nm), which was verified by inoculating the viruses on VeroE6 cells and confirming no viral replication for three consecutive passages. The UV inactivation treatment is intended to only affect the genomic material of the virus (RNA), therefore unaltering the external structure of the viral particles allowing their safely use in BSL2 laboratories ( Ruiz-Vega et al, 2022 ). SARS-CoV-2 samples at different titers (10 3 to 5 × 10 5 TCID50/mL) were prepared by serial dilution in standard buffer (HEPES 50 mM pH 7.4) and flowed over the biomimetic scaffold on the sensor surface.…”

“…To our knowledge, only a recent study has reported a plasmonic sensor for the quantification of whole SARS-CoV-2 virus particles, achieving a detection limit of 370 viral particles per mL (vp/mL) ( Huang et al, 2021 ), which is within the same range of our approach but using pseudotyped viruses, a secondary amplification step with gold nanoparticles, and not validated with real samples. On the other hand, our group developed a nanophotonic interferometric sensor for COVID-19 diagnostics demonstrating direct SARS-CoV-2 virus detection with detection limits below 100 TCID50/mL ( Ruiz-Vega et al, 2022 ). Herein, we have achieved similar results employing a conventional and user-friendly SPR technology with an innovative sensor biofunctionalization, which is considered to enhance the SARS-CoV-2 virus binding interaction by mimicking the human cell micro-environment.…”

“…The inactivated SARS-CoV-2 viruses Omicron BA.1 (hCoV-19/Italy/LAZ-INMI-2890/2021, GISAID accession ID EPI_ISL_7716384) and B1.617.2/delta (hCoV-19/Italy/LAZ-INMI-648/2021 GISAID accession ID EPI_ISL_2000624) were kindly provided by our collaborator Dr. Giulia Matusali from The National Institute of Infectious Diseases Lazzaro Spallanzani (INMI, Rome, Italy). The virus production and inactivation procedures have been described in ( Ruiz-Vega et al, 2022 ).…”

“…The main novelty and innovation of our work reside on a two-dimensional (2D) biomimetic assay approach employed to increase the reliability and transferability of the therapy screening tests while reducing the analysis times and the overall complexity of the evaluation study. Our biosensor is functionalized with an artificial cell membrane displaying the host cell receptors utilized by the SARS-CoV-2 for entry and infection, i.e., the angiotensin-converting enzyme 2 (ACE2), and the neutralization assay is performed with ultraviolet (UV)-inactivated SARS-CoV-2 viruses, which maintain the structural properties and protein activity and can be safely manipulated in P2-level biosafety laboratory installations ( Ruiz-Vega et al, 2022 ). With this methodology, we can more accurately simulate the virus-cell interaction during an infectivity assay – where both target molecules are anchored to their respective cell membranes - while eliminating the need of host cell culture procedures.…”

The Use of Sensors in Blood-Brain Barrier-on-a-Chip Devices: Current Practice and Future Directions

“…Another label-free, interferometric integrated optical biosensor construction is the bimodal waveguide interferometer, which technology has emerged in recent years. These devices have a small footprint and their performance has been demonstrated in the case of several target detection from fluid samples, e.g., microRNA marker [ 61 ], SARS-CoV-2 viral proteins [ 62 ], and bacteria [ 63 , 64 ]. The above-mentioned studies clearly show the impact of the application of such integrated optical interferometric biosensors in chip devices as incorporated sensors.…”