Sensitive Lateral Flow Immunoassay Based on Specific Peptide and Superior Oxidase Mimics with a Universal Dual-Mode...

Area of Science:

• Biotechnology
• Nanotechnology
• Immunodiagnostics

Background:

• Lateral flow immunoassays (LFIA) are vital for rapid infectious disease diagnosis.
• Developing specific biorecognition elements and signal amplification strategies for LFIA remains a challenge.
• Current methods often rely on antibodies, necessitating exploration of alternative recognition molecules.

Purpose of the Study:

• To develop a novel peptide-based lateral flow immunoassay (pLFIA) for sensitive SARS-CoV-2 S antigen detection.
• To identify a high-affinity peptide specific to the SARS-CoV-2 S antigen.
• To enhance signal amplification using a polydopamine nanosphere (PDA)@MnO2 nanocomposite for improved detection limits.

Main Methods:

• A specific peptide (WFLNDSELIML) binding to the SARS-CoV-2 S antigen was identified using biopanning.
• Molecular docking was employed to determine the peptide's binding site on the S antigen.
• A pLFIA was constructed using the identified peptide as a capture probe and a PDA@MnO2 nanocomposite as a colorimetric label for signal amplification.

Main Results:

• The identified peptide exhibited high affinity to the SARS-CoV-2 S antigen (dissociation constant: 9.29 ± 1.55 nM).
• The PDA@MnO2-based pLFIA achieved a limit of detection of 8.01 pg/mL for the S antigen, significantly lower than conventional methods.
• The assay demonstrated the ability to detect SARS-CoV-2 pseudoviruses in spiked saliva samples.

Conclusions:

• A highly sensitive and specific peptide-based lateral flow immunoassay (pLFIA) for SARS-CoV-2 antigen detection was successfully developed.
• The use of a PDA@MnO2 nanocomposite provides dual-mode signal amplification, enhancing assay performance.
• This pLFIA offers a promising and reliable tool for the rapid diagnosis of SARS-CoV-2 infections.