Minute-scale detection of SARS-CoV-2 using a low-cost biosensor composed of pencil graphite electrodes

Author(s)

de Lima, Lucas F. ^{[1, 2, 3, 4, 5, 6, 7, 8]} ; Ferreira, Andre L. ^{[1, 2, 3, 4, 5, 6, 7, 8]} ; Torres, Marcelo D. T. ^{[1, 2, 3, 4, 5, 6, 7]} ; de Araujo, William R. ^[8] ; de la Fuente-Nunez, Cesar ^{[1, 2, 3, 4, 5, 6, 7]}

Affiliation

^[1] Univ Penn, Sch Engn & Appl Sci, Dept Bioengn, Philadelphia, PA 19104 - USA

^[2] Univ Penn, Sch Engn & Appl Sci, Dept Chem & Biomol Engn, Philadelphia, PA 19104 - USA

^[3] Univ Penn, Penn Inst Computat Sci, Philadelphia, PA 19104 - USA

^[4] Univ Penn, Dept Psychiat, Machine Biol Grp, Philadelphia, PA 19104 - USA

^[5] Univ Penn, Dept Microbiol, Machine Biol Grp, Philadelphia, PA 19104 - USA

^[6] Univ Penn, Perelman Sch Med, Inst Biomed Informat, Philadelphia, PA 19104 - USA

^[7] Univ Penn, Perelman Sch Med, Inst Translat Med & Therapeut, Philadelphia, PA 19104 - USA

^[8] Univ Estadual Campinas, Inst Chem, Dept Analyt Chem, Portable Chem Sensors Lab, BR-13083970 Sao Paulo - Brazil

• Document type: Journal article
• Source: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA; v. 118, n. 30 JUL 27 2021.
• Web of Science Citations: 0

Abstract

COVID-19 has led to over 3.47 million deaths worldwide and continues to devastate primarily middle- and low-income countries. High-frequency testing has been proposed as a potential solution to prevent outbreaks. However, current tests are not sufficiently low-cost, rapid, or scalable to enable broad COVID-19 testing. Here, we describe LEAD (Low-cost Electrochemical Advanced Diagnostic), a diagnostic test that detects severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within 6.5 min and costs \$1.50 per unit to produce using easily accessible and commercially available materials. LEAD is highly sensitive toward SARS-CoV-2 spike protein (limit of detection = 229 fg center dot mL-1) and displays an excellent performance profile using clinical saliva (100.0% sensitivity, 100.0% specificity, and 100.0% accuracy) and nasopharyngeal/oropharyngeal (88.7% sensitivity, 86.0% specificity, and 87.4% accuracy) samples. No crossreactivity was detected with other coronavirus or influenza strains. Importantly, LEAD also successfully diagnosed the highly contagious SARS-CoV-2 B.1.1.7 UK variant. The device presents high reproducibility under all conditions tested and preserves its original sensitivity for 5 d when stored at 4 degrees C in phosphate-buffered saline. Our lowcost and do-it-yourself technology opens new avenues to facilitate high-frequency testing and access to much-needed diagnostic tests in resource-limited settings and low-income communities. (AU)

• FAPESP's process: 18/08782-1 - Miniaturized and integrated chemical sensors: new fabrication platforms for biological, clinical and environmental applications
• Grantee: Mauro Bertotti
• Support Opportunities: Research Projects - Thematic Grants