Colorimetric and electrochemical detection of SARS-CoV-2 spike antigen with a gold nanoparticle-based biosensor

• Published in: Analytica chimica acta Vol. 1182; p. 338939
• Main Authors: Karakuş, Erman, Erdemir, Eda, Demirbilek, Nisa, Liv, Lokman
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 16.10.2021
• Subjects: Biosensing Techniques; Colorimetric biosensor; Colorimetry; COVID-19; Dual-sensing probe; Electrochemical biosensor; Gold; Gold nanoparticles; Humans; Influenza A Virus, H1N1 Subtype; Metal Nanoparticles; SARS-CoV-2; COVID-19; SARS-CoV-2; Electrochemical biosensor; Dual-sensing probe; Colorimetric biosensor; Gold nanoparticles
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2021.338939

Since emerging in China in December 2019, COVID-19 has spread globally, wreaked havoc for public health and economies worldwide and, given the high infectivity and unexpectedly rapid spread of the virus responsible—that is, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)—urged the World Health Organization to declare it a pandemic. In response, reducing the virus's adverse effects requires developing methods of early diagnosis that are reliable, are inexpensive and offer rapid response. As demonstrated in this article, the colorimetric and electrochemical detection of SARS-CoV-2 spike antigen with gold nanoparticle-based biosensors may be one such method. In the presence of the SARS-CoV-2 spike antigen, gold nanoparticles aggregated rapidly and irreversibly due to antibody–antigen interaction and consequently changed in colour from red to purple, as easily observable with the naked eye or UV–Vis spectrometry by way of spectral redshifting with a detection limit of 48 ng/mL. Moreover, electrochemical detection was achieved by dropping developed probe solution onto the commercially available and disposable screen-printed gold electrode without requiring any electrode preparation and modification. The method identified 1 pg/mL of the SARS-CoV-2 spike antigen and showed a linear response to the SARS-CoV-2 spike antigen ranging from 1 pg/mL to 10 ng/mL. Both methods were highly specific to detecting the SARS-CoV-2 spike antigen but not other antigens, including influenza A (i.e. H1N1), MERS-CoV and Streptococcus pneumoniae, even at high concentrations. [Display omitted] •The developed probe (AuNP-mAb) exhibits dual sensing mode for the detection of SARS-CoV-2 spike antigen (S-Ag).•AuNP-mAb allows viusal detection (colorimetric) of S-Ag with a detection limit of 48 ng/mL.•Electrochemical detection of S-Ag is achieved by a disposable screen-printed gold electrode with a detection limit of 1 pg/mL.•Neither method exhibits cross-reactivity with other viral proteins such as Influenza A, MERS-CoV and Streptococcus pneumoniae.•AuNP-mAb allows simple and rapid analysis of S-Ag in saliva sample.