An Electrochemical Immunosensor Based on Carboxylated Graphene/SPCE for IgG-SARS-CoV-2 Nucleocapsid Determination
Luciana de Souza Freire,
Camila Macena Ruzo,
Bárbara Batista Salgado,
Ariamna María Dip Gandarilla,
Yonny Romaguera-Barcelay,
Ana P. M. Tavares,
Maria Goreti Ferreira Sales,
Isabelle Cordeiro,
Jaila Dias Borges Lalwani,
Robert Matos,
Henrique Fonseca Filho,
Spartaco Astolfi-Filho,
Ştefan Ţălu,
Pritesh Lalwani,
Walter Ricardo Brito
Affiliations
Luciana de Souza Freire
Department of Chemistry, Institute of Exact Sciences, Federal University of Amazonas, Manaus 69067-005, AM, Brazil
Camila Macena Ruzo
Department of Chemistry, Institute of Exact Sciences, Federal University of Amazonas, Manaus 69067-005, AM, Brazil
Bárbara Batista Salgado
Instituto Leônidas e Maria Deane (ILMD), Fiocruz Amazônia, Manaus 69067-005, AM, Brazil
Ariamna María Dip Gandarilla
Department of Chemistry, Institute of Exact Sciences, Federal University of Amazonas, Manaus 69067-005, AM, Brazil
Yonny Romaguera-Barcelay
Department of Chemistry, Institute of Exact Sciences, Federal University of Amazonas, Manaus 69067-005, AM, Brazil
Ana P. M. Tavares
BioMark@UC, Department of Chemical Engineering, Faculty of Sciences and Technology, University of Coimbra, 3030-790 Coimbra, Portugal
Maria Goreti Ferreira Sales
BioMark@UC, Department of Chemical Engineering, Faculty of Sciences and Technology, University of Coimbra, 3030-790 Coimbra, Portugal
Isabelle Cordeiro
Department of Physiological Sciences, Institute of Biological Sciences, Federal University of Amazonas, Manaus 69067-005, AM, Brazil
Jaila Dias Borges Lalwani
Faculty of Pharmaceutical Sciences, Federal University of Amazonas, Manaus 69067-005, AM, Brazil
Robert Matos
Amazonian Materials Group, Federal University of Amapá (UNIFAP), Macapá 49100-000, AP, Brazil
Henrique Fonseca Filho
Laboratory of Nanomaterials Synthesis and Nanoscopy (LSNN), Federal University of Amazonas (UFAM), Manaus 69067-005, AM, Brazil
Spartaco Astolfi-Filho
Department of Chemistry, Institute of Exact Sciences, Federal University of Amazonas, Manaus 69067-005, AM, Brazil
Ştefan Ţălu
The Directorate of Research, Development and Innovation Management (DMCDI), The Technical University of Cluj-Napoca, Constantin Daicoviciu Street, No. 15, 400020 Cluj-Napoca, Romania
Pritesh Lalwani
Instituto Leônidas e Maria Deane (ILMD), Fiocruz Amazônia, Manaus 69067-005, AM, Brazil
Walter Ricardo Brito
Department of Chemistry, Institute of Exact Sciences, Federal University of Amazonas, Manaus 69067-005, AM, Brazil
The COVID-19 pandemic has emphasized the importance and urgent need for rapid and accurate diagnostic tests for detecting and screening this infection. Our proposal was to develop a biosensor based on an ELISA immunoassay for monitoring antibodies against SARS-CoV-2 in human serum samples. The nucleocapsid protein (N protein) from SARS-CoV-2 was employed as a specific receptor for the detection of SARS-CoV-2 nucleocapsid immunoglobulin G. N protein was immobilized on the surface of a screen-printed carbon electrode (SPCE) modified with carboxylated graphene (CG). The percentage of IgG-SARS-CoV-2 nucleocapsid present was quantified using a secondary antibody labeled with horseradish peroxidase (HRP) (anti-IgG-HRP) catalyzed using 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 detection limit calculated was 1:4947 v/v. The chronoamperometric method showed electrical signals directly proportional to antibody concentrations due to antigen-antibody (Ag-Ab) specific and stable binding reaction.
