COVID-19 diagnosis by SARS-CoV-2 Spike protein detection in saliva using an ultrasensitive magneto-assay based on disposable electrochemical sensor

Author(s)

Nascimento, Evair D. ; Fonseca, Wilson T. ; de Oliveira, Tassia R. ; de Correia, Camila R. S. T. B. ; Faca, Vitor M. ; de Morais, Beatriz P. ; Silvestrini, Virginia C. ; Pott-Junior, Henrique ; Teixeira, Felipe R. ; Faria, Ronaldo C.

• Document type: Journal article
• Source: SENSORS AND ACTUATORS B-CHEMICAL; v. 353, p. 9-pg., 2022-02-15.

Abstract

The outbreak of the COVID-19 pandemic, caused by Severe Acute Respiratory Syndrome of Coronavirus 2 (SARS-CoV-2), has fueled the search for diagnostic tests aiming at the control and reduction of the viral transmission. The main technique used for diagnosing the Coronavirus disease (COVID-19) is the reverse transcriptionpolymerase chain reaction (RT-PCR) technique. However, considering the high number of cases and the underlying limitations of the RT-PCR technique, especially with regard to accessibility and cost of the test, one does not need to overemphasize the need to develop new and less expensive testing techniques that can aid the early diagnosis of the disease. With that in mind, we developed an ultrasensitive magneto-assay using magnetic beads and gold nanoparticles conjugated to human angiotensin-converting enzyme 2 (ACE2) peptide (Gln(24)-Gln(42)) for the capturing and detection of SARS-CoV-2 Spike protein in human saliva. The technique applied involved the use of a disposable electrochemical device containing eight screen-printed carbon electrodes which allow the simultaneous analysis of eight samples. The magneto-assay exhibited an ultralow limit of detection of 0.35 ag mL(-1) for the detection of SARS-CoV-2 Spike protein in saliva. The magneto-assay was tested in saliva samples from healthy and SARS-CoV-2-infected individuals. In terms of efficiency, the proposed technique - which presented a sensitivity of 100.0% and specificity of 93.7% for SARS-CoV-2 Spike protein-exhibited great similarity with the RT-PCR technique. The results obtained point to the application potential of this simple, low-cost magneto-assay for saliva-based point-of-care COVID-19 diagnosis. (AU)

• FAPESP's process: 19/03943-0 - Cloning of Fbxl17 domains in bacterial expression vectors
• Grantee: Camila Rolemberg Santana Travaglini Berti de Correia
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• FAPESP's process: 16/25798-3 - Functional consequences of rearrangements to the FBXL17 gene detected in patient samples and cancer cell lines, on the E3 ubiquitin-ligase SCF(Fbxl17) activity
• Grantee: Felipe Roberti Teixeira
• Support Opportunities: Regular Research Grants
• FAPESP's process: 20/12920-0 - Application of natural SARS-CoV-2 proteins to aid the development of new diagnostic strategies for COVID-19
• Grantee: Vitor Marcel Faça
• Support Opportunities: Regular Research Grants
• FAPESP's process: 20/04635-4 - Development of a simple and affordable disposable device for rapid diagnosis of coronavirus (SARS-CoV-2)
• Grantee: Ronaldo Censi Faria
• Support Opportunities: Regular Research Grants
• FAPESP's process: 20/07539-6 - Development of a simple and affordable disposable device for rapid diagnosis of Coronavirus (SARS-CoV-2)
• Grantee: Tássia Regina de Oliveira
• Support Opportunities: Scholarships in Brazil - Post-Doctoral