Flexible Label-Free Platinum and Bio-PET-Based Immunosensor for the Detection of SARS-CoV-2

• Published in: Biosensors (Basel) 2023-01, Vol.13 (2), p.190
• Main Authors: Blasques, Rodrigo Vieira, de Oliveira, Paulo Roberto, Kalinke, Cristiane, Brazaca, Laís Canniatti, Crapnell, Robert D, Bonacin, Juliano Alves, Banks, Craig E, Janegitz, Bruno Campos
• Format: Article
• Language: English
• Subjects: 3D printing technology; Bio-PET; Biocompatibility; Biomarkers; Biosensing Techniques - methods; Biosensors; Cardiovascular disease; Chloride; Contact angle; Coronaviruses; COVID-19; Cysteine; Diagnostic tests; Electrochemical impedance spectroscopy; Electrochemical Techniques - methods; Electrochemistry; Electrodes; Ferricyanide; flexible electrode; Humans; Immunoassay - methods; Immunosensors; Medical screening; Platinum; platinum-based electrode; point-of-care; Polyethylene terephthalate; Portable equipment; Potassium; Proteins; Saliva; SARS-CoV-2; SARS-CoV-2 diagnostics; Sensors; Severe acute respiratory syndrome coronavirus 2; Sodium; Software; Spectroscopy; Spike protein; Square waves; Substrates; Sustainable materials; Sustainable use; Technology application; Thin films; Three dimensional printing; Voltammetry
• ISSN: 2079-6374; 2079-6374
• DOI: 10.3390/bios13020190

The demand for new devices that enable the detection of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) at a relatively low cost and that are fast and feasible to be used as point-of-care is required overtime on a large scale. In this sense, the use of sustainable materials, for example, the bio-based poly (ethylene terephthalate) (Bio-PET) can be an alternative to current standard diagnostics. In this work, we present a flexible disposable printed electrode based on a platinum thin film on Bio-PET as a substrate for the development of a sensor and immunosensor for the monitoring of COVID-19 biomarkers, by the detection of L-cysteine and the SARS-CoV-2 spike protein, respectively. The electrode was applied in conjunction with 3D printing technology to generate a portable and easy-to-analyze device with a low sample volume. For the L-cysteine determination, chronoamperometry was used, which achieved two linear dynamic ranges (LDR) of 3.98-39.0 μmol L and 39.0-145 μmol L , and a limit of detection (LOD) of 0.70 μmol L . The detection of the SARS-CoV-2 spike protein was achieved by both square wave voltammetry (SWV) and electrochemical impedance spectroscopy (EIS) by a label-free immunosensor, using potassium ferro-ferricyanide solution as the electrochemical probe. An LDR of 0.70-7.0 and 1.0-30 pmol L , with an LOD of 0.70 and 1.0 pmol L were obtained by SWV and EIS, respectively. As a proof of concept, the immunosensor was successfully applied for the detection of the SARS-CoV-2 spike protein in enriched synthetic saliva samples, which demonstrates the potential of using the proposed sensor as an alternative platform for the diagnosis of COVID-19 in the future.