Gold-binding peptide as a selective layer for electrochemical detection of SARS-CoV-2 antibodies

• Published in: Talanta (Oxford) 2023-05, Vol.257, p.124348-124348, Article 124348
• Main Authors: Braz, Beatriz A., Hospinal-Santiani, Manuel, Martins, Gustavo, Gogola, Jeferson L., Valenga, Marcia G.P., Beirão, Breno C.B., Bergamini, Márcio F., Marcolino-Junior, Luiz H., Thomaz-Soccol, Vanete, Soccol, Carlos R.
• Format: Article
• Language: English
• Subjects: Antibodies, Viral; Biosensing Techniques - methods; COVID-19; Electrochemical immunosensor; Electrochemical Techniques - methods; Gold - chemistry; Gold nanoparticles; Humans; Immunoassay - methods; Metal Nanoparticles - chemistry; Peptides; SARS-CoV-2; Solid-binding peptide
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2023.124348

Electrochemical immunosensors are excellent alternatives to prepare portable platforms used for rapid and inexpensive diagnostic of infectious diseases such as the recently emerged COVID-19. Incorporating synthetic peptides as selective recognition layers combined with nanomaterials such as gold nanoparticles (AuNPs) can significantly enhance the analytical performance of immunosensors. In the present study, an electrochemical immunosensor based on solid-binding peptide was built and evaluated towards SARS-CoV-2 Anti-S antibodies detection. The peptide used as recognition site has two important portions: one based on the viral receptor binding domain (RBD), capable of recognizing antibodies of the spike protein (Anti-S), and another suitable for interacting with gold nanoparticles. Gold-binding peptide (Pept/AuNP) dispersion was used directly to modify a screen-printed carbon electrode (SPE). The voltammetric behavior of the [Fe(CN)6]3-/4- probe after every construction and detection step was recorded using cyclic voltammetry by assessing the stability of the Pept/AuNP as a recognition layer onto the electrode surface. Differential pulse voltammetry was used as a detection technique, and a linear working range from 75 ng mL−1 to 15 μg mL−1 was established, with 1.059 μA dec−1 of sensitivity and R2 = 0.984. The response selectivity against SARS-CoV-2 Anti-S antibodies was investigated in presence of concomitant species. The immunosensor was used to detect SARS-CoV-2 Anti-spike protein (Anti-S) antibodies in human serum samples, successfully differentiating between negative and positive responses of samples at a 95% confidence level. Therefore, the gold-binding peptide is a promising tool to be applied as a selective layer for antibody detection. [Display omitted] •Specific synthesis of solid-binding peptide with affinity to gold and SARS-CoV-2 made in a single step.•Detection of SARS-CoV-2 antibodies based on gold-binding peptide as a recognition site.•Screen-printed electrode as disposable platform for SARS-CoV-2 immunosensor construction.•First step towards the development of electrochemical POC devices for trials of relevant diseases.