Graphene-Binding Peptide in Fusion with SARS-CoV-2 Antigen for Electrochemical Immunosensor Construction.
Beatriz A BrazManuel Hospinal-SantianiGustavo MartinsCristian S PintoAldo J G ZarbinBreno C B BeirãoVanete Thomaz-SoccolMárcio Fernando BergaminiLuiz H Marcolino-JuniorCarlos Ricardo SoccolPublished in: Biosensors (2022)
The development of immunosensors to detect antibodies or antigens has stood out in the face of traditional methods for diagnosing emerging diseases such as the one caused by the SARS-CoV-2 virus. The present study reports the construction of a simplified electrochemical immunosensor using a graphene-binding peptide applied as a recognition site to detect SARS-CoV-2 antibodies. A screen-printed electrode was used for sensor preparation by adding a solution of peptide and reduced graphene oxide (rGO). The peptide-rGO suspension was characterized by scanning electron microscopy (SEM), Raman spectroscopy, and Fourier transform infrared spectroscopy (FT-IR). The electrochemical characterization (electrochemical impedance spectroscopy-EIS, cyclic voltammetry-CV and differential pulse voltammetry-DPV) was performed on the modified electrode. The immunosensor response is based on the decrease in the faradaic signal of an electrochemical probe resulting from immunocomplex formation. Using the best set of experimental conditions, the analytic curve obtained showed a good linear regression (r 2 = 0.913) and a limit of detection (LOD) of 0.77 μg mL -1 for antibody detection. The CV and EIS results proved the efficiency of device assembly. The high selectivity of the platform, which can be attributed to the peptide, was demonstrated by the decrease in the current percentage for samples with antibody against the SARS-CoV-2 S protein and the increase in the other antibodies tested. Additionally, the DPV measurements showed a clearly distinguishable response in assays against human serum samples, with sera with a response above 95% being considered negative, whereas responses below this value were considered positive. The diagnostic platform developed with specific peptides is promising and has the potential for application in the diagnosis of other infections that lead to high antibody titers.
Keyphrases
- label free
- sars cov
- gold nanoparticles
- reduced graphene oxide
- molecularly imprinted
- respiratory syndrome coronavirus
- electron microscopy
- high throughput
- ionic liquid
- raman spectroscopy
- carbon nanotubes
- risk assessment
- sensitive detection
- quantum dots
- dendritic cells
- room temperature
- electronic health record
- binding protein
- coronavirus disease
- solid phase extraction
- single molecule
- magnetic resonance imaging
- solid state
- liquid chromatography
- drug induced