A paper-based optical sensor for the screening of viruses through the cysteine residues of their surface proteins: A proof of concept on the detection of coronavirus infection

Mahnaz D Gholami; Kristyan Guppy-Coles; Serena Nihal; Daman Langguth; Prashant Sonar; Godwin A Ayoko; Chamindie Punyadeera; Emad L Izake

doi:10.1016/j.talanta.2022.123630

A paper-based optical sensor for the screening of viruses through the cysteine residues of their surface proteins: A proof of concept on the detection of coronavirus infection

Talanta. 2022 Oct 1:248:123630. doi: 10.1016/j.talanta.2022.123630. Epub 2022 May 31.

Authors

Mahnaz D Gholami¹, Kristyan Guppy-Coles¹, Serena Nihal¹, Daman Langguth², Prashant Sonar³, Godwin A Ayoko⁴, Chamindie Punyadeera⁵, Emad L Izake⁶

Affiliations

¹ School of Chemistry and Physics, Faculty of Science, Queensland University of Technology (QUT), Brisbane, QLD, 4000, Australia.
² Department of Clinical Immunology and Allergy, Wesley Hospital, Brisbane, QLD, 4066, Australia; Department of Immunology, Sullivan Nicolaides Pathology, QLD, 4006, Australia.
³ School of Chemistry and Physics, Faculty of Science, Queensland University of Technology (QUT), Brisbane, QLD, 4000, Australia; Centre for Materials Science, Queensland University of Technology (QUT), Brisbane, QLD, 4000, Australia; Centre for Biomedical Technology, Queensland University of Technology (QUT), Brisbane, QLD, 4000, Australia.
⁴ School of Chemistry and Physics, Faculty of Science, Queensland University of Technology (QUT), Brisbane, QLD, 4000, Australia; Centre for Materials Science, Queensland University of Technology (QUT), Brisbane, QLD, 4000, Australia.
⁵ Griffith Institute for Drug Discovery (GRIDD), Griffith University, Brisbane, QLD, 4111, Australia; Menzies Health Institute Queensland (MIHQ), Griffith University, Brisbane, QLD, 4111, Australia.
⁶ School of Chemistry and Physics, Faculty of Science, Queensland University of Technology (QUT), Brisbane, QLD, 4000, Australia; Centre for Materials Science, Queensland University of Technology (QUT), Brisbane, QLD, 4000, Australia; Centre for Biomedical Technology, Queensland University of Technology (QUT), Brisbane, QLD, 4000, Australia. Electronic address: e.kiriakous@qut.edu.au.

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a serious threat to human health. Current methods such as reverse transcription polymerase chain reaction (qRT-PCR) are complex, expensive, and time-consuming. Rapid, and simple screening methods for the detection of SARS-CoV-2 are critically required to fight the current pandemic. In this work we present a proof of concept for, a simple optical sensing method for the screening of SARS-CoV-2 through its spike protein subunit S1. The method utilizes a target-specific extractor chip to bind the protein from the biological specimens. The disulfide bonds of the protein are then reduced into a biothiol with sulfhydryl (SH) groups that react with a blue-colored benzothiazole azo dye-Hg complex (BAN-Hg) and causes the spontaneous change of its blue color to pink which is observable by the naked eye. A linear relationship between the intensity of the pink color and the logarithm of reduced S1 protein concentration was found within the working range 130 ng.mL^-1-1.3 pg mL^-1. The lowest limit of detection (LOD) of the assay was 130 fg mL^-1. A paper based optical sensor was fabricated by loading the BAN-Hg sensor onto filter paper and used to screen the S1 protein in spiked saliva and patients' nasopharyngeal swabs. The results obtained by the paper sensor corroborated with those obtained by qRT-PCR. The new paper-based sensing method can be extended to the screening of many viruses (e.g. the human immunodeficiency virus, the human polyomavirus, the human papilloma virus, the adeno associated viruses, the enteroviruses) through the cysteine residues of their capsid proteins. The new method has strong potential for screening viruses at pathology labs and in remote areas that lacks advanced scientific infrastructure. Further clinical studies are warranted to validate the new sensing method.

Keywords: Biothiol; Colorimetric assay; Paper based sensor; SARS-CoV-2.

MeSH terms

COVID-19* / diagnosis
Cysteine
Humans
Membrane Proteins
Mercury*
SARS-CoV-2 / genetics

Substances

Membrane Proteins
Mercury
Cysteine