Electrochemical biosensor for diagnosis of covid-19 based on spike protein
Sars-cov-2 is composed of four structural proteins: spike protein, nucleocapsid protein, envelope protein and membrane protein (as shown in Figure 1). Among them, spike protein is a target protein that can be used to diagnose covid-19. It has high immunogenicity and receptor binding domain (RBD). Therefore, it is of great significance to use the spike protein of sars-cov-2 in the diagnosis of covid-19 and the development of vaccines and related therapeutic drugs. Based on this, a large number of scholars have designed a variety of electrochemical biosensors to detect sars-cov-2.
The graphene electrode of FET was modified with 1-Pyrene butyric acid N-hydroxysuccinimide ester (pbase), which was used as the interface coupling agent to fix the sars-cov-2 spike protein specific antibody (as shown in Figure 2a), and then the FET was completely covered with phosphate buffered saline (PBS, pH 7.4) as the electrolyte. The clinical sample detection of sars-cov-2 was realized based on the potential change on the surface of the pipeline and the influence on the electrical response, The detection limit of clinical samples was 2.42 × 102 copies/mL。 The electrochemical biosensor based on FET has the advantages of low cost, high sensitivity and wide dynamic response range.