Colorimetric Cotton Swab for Viral Protease Detection

Area of Science:

• Biochemistry
• Molecular Biology
• Virology

Background:

• Accurate detection of active viral infections is crucial for effective treatment and public health strategies.
• Distinguishing between active and resolved infections requires sensitive diagnostic tools that report viral activity.

Purpose of the Study:

• To develop a simple, rapid, point-of-care colorimetric assay for detecting the activity of a specific viral protease.
• To establish a proof-of-concept using the SARS-CoV-2 main protease (Mpro) for active infection detection.

Main Methods:

• Design and synthesis of a novel chromophore reporter (CoV2-AMG) based on 4-aminomalachite green (4-AMG).
• Demonstration of selective color conversion upon interaction with SARS-CoV-2 Mpro.
• Evaluation of visual and smartphone-based detection capabilities.

Main Results:

• The CoV2-AMG reporter exhibited high selectivity for SARS-CoV-2 Mpro, with no observable color change for other viral proteases.
• A distinct color change was observed, detectable by the naked eye and smartphone imaging.
• The assay demonstrated a low limit of detection, indicating high sensitivity.

Conclusions:

• A straightforward colorimetric method for reporting viral protease activity has been developed.
• This approach offers a promising strategy for rapid point-of-care detection of active SARS-CoV-2 infections.
• The method's simplicity and generalizability hold potential for combating future viral outbreaks.