de Souza Freire, L.; Ruzo, C.M.; Salgado, B.B.; Gandarilla, A.M.D.; Romaguera-Barcelay, Y.; Tavares, A.P.M.; Sales, M.G.F.; Cordeiro, I.; Lalwani, J.D.B.; Matos, R.; Fonseca Filho, H.; Astolfi-Filho, S.; Ţălu, Ş.; Lalwani, P.; Brito, W.R. An Electrochemical Immunosensor Based on Carboxylated Graphene/SPCE for IgG-SARS-CoV-2 Nucleocapsid Determination. Biosensors2022, 12, 1161.
de Souza Freire, L.; Ruzo, C.M.; Salgado, B.B.; Gandarilla, A.M.D.; Romaguera-Barcelay, Y.; Tavares, A.P.M.; Sales, M.G.F.; Cordeiro, I.; Lalwani, J.D.B.; Matos, R.; Fonseca Filho, H.; Astolfi-Filho, S.; Ţălu, Ş.; Lalwani, P.; Brito, W.R. An Electrochemical Immunosensor Based on Carboxylated Graphene/SPCE for IgG-SARS-CoV-2 Nucleocapsid Determination. Biosensors 2022, 12, 1161.
de Souza Freire, L.; Ruzo, C.M.; Salgado, B.B.; Gandarilla, A.M.D.; Romaguera-Barcelay, Y.; Tavares, A.P.M.; Sales, M.G.F.; Cordeiro, I.; Lalwani, J.D.B.; Matos, R.; Fonseca Filho, H.; Astolfi-Filho, S.; Ţălu, Ş.; Lalwani, P.; Brito, W.R. An Electrochemical Immunosensor Based on Carboxylated Graphene/SPCE for IgG-SARS-CoV-2 Nucleocapsid Determination. Biosensors2022, 12, 1161.
de Souza Freire, L.; Ruzo, C.M.; Salgado, B.B.; Gandarilla, A.M.D.; Romaguera-Barcelay, Y.; Tavares, A.P.M.; Sales, M.G.F.; Cordeiro, I.; Lalwani, J.D.B.; Matos, R.; Fonseca Filho, H.; Astolfi-Filho, S.; Ţălu, Ş.; Lalwani, P.; Brito, W.R. An Electrochemical Immunosensor Based on Carboxylated Graphene/SPCE for IgG-SARS-CoV-2 Nucleocapsid Determination. Biosensors 2022, 12, 1161.
Abstract
The COVID-19 pandemic has highlighted the importance and urgent need of rapid and accurate diagnostic tests for detection and screening of this infection. In our proposal, a biosensor based on the ELISA immunoassay was developed for monitoring antibodies against SARS-CoV-2 in human serum samples. The SARS-CoV-2 nucleocapsid protein (N-protein) was selected as a specific receptor for the detection of SARS-CoV-2 nucleocapsid immunoglobulin G. Thus, the N-protein was immobilized on surface of screen-printed carbon electrode (SPCE) modified with carboxylated graphene (CG). The IgG-SARS-CoV-2 nucleocapsid concentration was quantified using a secondary antibody labelled with horseradish peroxidase (HRP) (anti-IgG-HRP) catalyzed by 3,3’,5,5’-tetramethylbenzidine (TMB) mediator by chronoamperometry. A linear response was obtained in the range of 1:1000-1:200 v/v in phosphate buffer solution (PBS) and the limit of detection calculated was of 1:4947 v/v. The chronoamperometric method showed electrical signals directly proportional to antibody concentrations due to Ag-Ab specific and stable binding reaction.
Keywords
Immunosensor; SARS-CoV-2; N-protein
Subject
Chemistry and Materials Science, Electrochemistry
Copyright:
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