Sustainable Electrochemical-Magnetic Biosensor Fabricated from Recycled Materials for Label-Free Detection of SARS-CoV-2 in Human Saliva
Caio Lenon Chaves Carvalho, Steffane Q. Nascimento, Thiago Bertaglia, Luana Cristina Italiano Faria, Erika R. Manuli, Geovana M. Pereira, Welter Cantanhêde, Carlos M. Costa, Josu Fernández Maestu, S. Lanceros‐Méndez, Osvaldo N. Oliveira, Éster Cerdeira Sabino, Frank N. Crespilho
Abstract
High Resolution Image Download MS PowerPoint Slide The COVID-19 pandemic has highlighted the critical need for scalable, rapid, and cost-effective diagnostic solutions, especially in resource-limited settings. In this study, we developed a sustainable magnetic electrochemical biosensor for the mass testing of SARS-CoV-2, emphasizing affordability, environmental impact reduction, and clinical applicability. By leveraging recycled materials from spent batteries and plastics, we achieved a circular economy-based fabrication process with a recyclability rate of 98.5%. The biosensor employs MnFe 2 O 4 nanoparticles functionalized with anti-SARS-CoV-2 antibodies, integrated into a 3D-printed electrochemical device for decentralized testing. Advanced characterization confirmed the biosensor’s robust performance, including high sensitivity (LOD: 3.46 pg mL –1 ) and specificity, with results demonstrating a 95% correlation to RT-PCR gold standard testing. The cost of materials used per biosensor test is only USD 0.2, making it highly affordable and suitable for large-scale production using additive manufacturing. Key features include simple preparation, rapid response, and reusability, making it ideal for point-of-care diagnostics. Beyond COVID-19, this platform’s modularity allows for adaptation to other viral diseases, offering a versatile solution to global diagnostic challenges. This work highlights the potential of integrating electrochemical sensing with sustainable practices to address healthcare inequities and reduce environmental impact.