Self-assembled chromogen-loaded polymeric cocoon for respiratory virus detection

Area of Science:

• Nanotechnology
• Biochemistry
• Analytical Chemistry

Background:

• The development of sensitive and rapid diagnostic tools for airborne respiratory viruses is crucial for public health.
• Existing methods for virus detection can be complex, time-consuming, or lack sufficient sensitivity.

Purpose of the Study:

• To develop a novel colorimetric immunoassay for the highly sensitive detection of influenza virus (IV)/A.
• To utilize self-assembled nanoparticles and a nanozyme-based system for enhanced signal amplification.

Main Methods:

• Co-precipitation of 3,3',5,5'-tetramethylbenzidine (TMB) to form TMB nanoparticles (TMB-NPs).
• Encapsulation of TMB-NPs within poly(lactide-co-glycolide) (PLGA) nanovesicles (TMB-NPs@PLGA).
• Development of an immunoassay involving antibody-conjugated TMB-NPs@PLGA, antigen capture, PLGA dissolution, and TMB-catalyzed oxidation by H2O2 using copper nanoflowers (CuNFs) as nanozymes.

Main Results:

• The developed immunoassay achieved a low limit of detection (LOD) of 32.37 fg mL⁻¹ for IV/A in buffer and 54.97 fg mL⁻¹ in serum.
• The sensor successfully detected a clinically isolated IV/A/H3N2 strain with an LOD of 17 plaque-forming units (pfu) mL⁻¹ and SARS-CoV-2 spike protein with an LOD of 143 fg mL⁻¹.
• The TMB-NPs@PLGA system demonstrated effective signal enrichment and amplification for colorimetric detection.

Conclusions:

• The TMB-NPs@PLGA-based colorimetric sensor offers a highly sensitive and effective platform for detecting airborne respiratory viruses.
• This approach holds significant promise for the development of rapid and reliable diagnostic tools for infectious diseases.
• The integration of self-assembly, nanoencapsulation, and nanozyme catalysis provides a powerful strategy for sensitive biosensing.