Colorimetric and Electrochemical Methods for the Detection of SARS-CoV-2 Main Protease by Peptide-Triggered Assembly of Gold Nanoparticles

Abstract

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) main protease (Mpro) has been regarded as one of the ideal targets for the development of antiviral drugs. The currently used methods for the probing of Mpro activity and the screening of its inhibitors require the use of a double-labeled peptide substrate. In this work, we suggested that the label-free peptide substrate could induce the aggregation of AuNPs through the electrostatic interactions, and the cleavage of the peptide by the Mpro inhibited the aggregation of AuNPs. This fact allowed for the visual analysis of Mpro activity by observing the color change of the AuNPs suspension. Furthermore, the co-assembly of AuNPs and peptide was achieved on the peptide-covered electrode surface. Cleavage of the peptide substrate by the Mpro limited the formation of AuNPs/peptide assembles, thus allowing for the development of a simple and sensitive electrochemical method for Mpro detection in serum samples. The change of the electrochemical signal was easily monitored by electrochemical impedance spectroscopy (EIS). The detection limits of the colorimetric and electrochemical methods are 10 and 0.1 pM, respectively. This work should be valuable for the development of effective antiviral drugs and the design of novel optical and electrical biosensors.

The role of electrochemical biosensors in SARS-CoV-2 detection: a bibliometrics-based analysis and review

“…For example, Aydın et al 62 coated 11-mercaptoundecanoic acid with gold nanoparticles to detect COVID 19 specific spike receptor-binding domain protein. Feng et al 63 developed an electrochemical and colorimetric biosensor based on peptide-triggered gold nanoparticle assembly to detect SARS-CoV-2 major protease.…”

Nanoscale Technologies in the Fight against COVID-19: From Innovative Nanomaterials to Computer-Aided Discovery of Potential Antiviral Plant-Derived Drugs

“…It became evident early on that severe COVID-19 is a systemic hyperinflammatory disease derived from the so-called cytokine storm, a term describing a condition of uncontrolled systemic hyperinflammation triggered by the release of a big amount of pro-inflammatory cytokines, such as IL-1, IL-6, IL-18, IFN- , and TNF- , among others [ 11 ]. To date, nanotechnological platforms have been explored for their employment in diseases due to several viruses [ 12 ], and for the development of new effective therapeutic treatments as well as diagnostic tools, innovative materials, and drugs useful for infection prevention and control [ 13 , 14 , 15 ].…”

A Self-Immolative Fluorescent Probe for Selective Detection of SARS-CoV-2 Main Protease

“… 14 Despite that fact that the levels of detection (LoDs) of the electrochemical sensors can be as low as 0.1 pM, these sensors rarely detect M pro in real cell samples due to their low electrochemical stability in cells. 14 Another useful approach for detecting M pro is the colorimetric sensor. 14 , 17 , 19 , 20 One representative gold nanoparticle-based colorimetric protease assay was reported by Willis and coauthors to detect the exogenously expressed M pro in HEK 293T cells.…”

“… 14 Another useful approach for detecting M pro is the colorimetric sensor. 14 , 17 , 19 , 20 One representative gold nanoparticle-based colorimetric protease assay was reported by Willis and coauthors to detect the exogenously expressed M pro in HEK 293T cells. 19 Meanwhile, based on the versatility of nanomaterials, 21 − 26 we developed sensitive colorimetric sensors for the detection of M pro .…”

“…Recently, many approaches have been developed for the detection of M pro , − among which electrochemical sensors, colorimetric sensors, and genetically encoded biosensors have been the most popular. In 2022, the Liu group developed a versatile electrochemical sensor that took advantage of the peptide-triggered assembly of gold nanoparticles to introduce an electrochemical signal for M pro detection .…”