Colorimetric Detection of SARS-CoV-2 Using Plasmonic Biosensors and Smartphones

Author(s):Show less -

Materon, Elsa M. ; Gomez, Faustino R. ; Almeida, Mariana B. ; Shimizu, Flavio M. ; Wong, Ademar ; Teodoro, Kelcilene B. R. ; Silva, Filipe S. R. ; Lima, Manoel J. A. ; Angelim, Monara Kaelle S. C. ; Melendez, Matias E. ; Porras, Nelson ; Vieira, Pedro M. ; Correa, Daniel S. ; Carrilho, Emanuel ; Oliveira Jr, Osvaldo N. ; Azevedo, Ricardo B. ; Goncalves, Debora

• Document type: Journal article
• Source: ACS APPLIED MATERIALS & INTERFACES; v. 14, n. 49, p. 12-pg., 2022-12-01.

Abstract

Low-cost, instrument-free colorimetric tests were developed to detect SARS-CoV-2 using plasmonic biosensors with Au nanoparticles functionalized with polyclonal antibodies (f-AuNPs). Intense color changes were noted with the naked eye owing to plasmon coupling when f-AuNPs form clusters on the virus, with high sensitivity and a detection limit of 0.28 PFU mL(-1) (PFU stands for plaque-forming units) in human saliva. Plasmon coupling was corroborated with computer simulations using the finite-difference time-domain (FDTD) method. The strategies based on preparing plasmonic biosensors with f-AuNPs are robust to permit SARS-CoV-2 detection via dynamic light scattering and UV-vis spectroscopy without interference from other viruses, such as influenza and dengue viruses. The diagnosis was made with a smartphone app after processing the images collected from the smartphone camera, measuring the concentration of SARS-CoV-2. Both image processing and machine learning algorithms were found to provide COVID-19 diagnosis with 100% accuracy for saliva samples. In subsidiary experiments, we observed that the biosensor could be used to detect the virus in river waters without pretreatment. With fast responses and requiring small sample amounts (only 20 mu L), these colorimetric tests can be deployed in any location within the point-of-care diagnosis paradigm for epidemiological control. (AU)

• FAPESP's process: 14/50867-3 - INCT 2014: National Institute of Science and Technology in Bioanalysis
• Grantee: Marco Aurelio Zezzi Arruda
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 17/03879-4 - EMU granted in the process 2013 / 14262-7 thematic project - DLS
• Grantee: Osvaldo Novais de Oliveira Junior
• Support Opportunities: Multi-user Equipment Program
• FAPESP's process: 19/19235-4 - Dispersive magnetic solid-phase microextraction employing microfluidic platform: application to multiplexed determinations of antibiotics, aflatoxins and the diagnosis Mastitis in milk
• Grantee: Manoel de Jesus de Aquino Lima
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 21/08387-8 - Construction of an ultrasensitive biosensor for CRISPR-Cas12-based diagnosis for SARS-CoV-2 and variants detection without nucleic acid amplification
• Grantee: Filipe Sampaio Reis da Silva
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 18/22214-6 - Towards a convergence of technologies: from sensing and biosensing to information visualization and machine learning for data analysis in clinical diagnosis
• Grantee: Osvaldo Novais de Oliveira Junior
• Support Opportunities: Research Projects - Thematic Grants