Signal enhancement strategy for a micro-arrayed polydiacetylene (PDA) immunosensor using enzyme-catalyzed...

Area of Science:

• Biomolecular Engineering
• Biosensor Technology
• Immunosensing

Background:

• Antibody-based immunosensors are crucial for detecting biomarkers.
• Polydiacetylene (PDA) liposomes offer unique signal transduction properties.
• Enhancing immunosensor sensitivity is critical for early disease detection.

Purpose of the Study:

• To develop a signal enhancement strategy for PDA liposome immunosensors.
• To improve the detection sensitivity for human immunoglobulin E (hIgE).
• To enable ultrasensitive and highly specific biosensing for various biomolecules.

Main Methods:

• Utilized PDA liposomes immobilized with anti-hIgE monoclonal antibodies.
• Implemented a two-step immunoresponse combining primary antigen-antibody reaction with a sandwich assay using HRP-conjugated polyclonal antibodies.
• Leveraged enzyme-catalyzed precipitate formation (HRP-catalyzed diaminobenzidine oxidation) to generate mechanical pressure and enhance fluorescence signals.

Main Results:

• Achieved detection of hIgE concentrations as low as 0.01 ng/mL.
• Demonstrated a 1000-fold increase in sensitivity compared to the primary immunoresponse.
• Showcased signal amplification through mechanical stimulation of PDA liposomes by enzyme-generated precipitate.

Conclusions:

• The proposed signal enhancement strategy significantly improves PDA liposome immunosensor sensitivity.
• Enzyme-catalyzed precipitate formation provides effective mechanical force for signal amplification.
• This approach is applicable for ultrasensitive detection of various biomolecules in diverse settings.