Signal enhancement of a micro-arrayed polydiacetylene (PDA) biosensor using gold nanoparticles

Area of Science:

• Biochemistry
• Materials Science
• Nanotechnology

Background:

• Polydiacetylene (PDA) liposomes exhibit stimulus-responsive colorimetric and fluorescent properties.
• They are widely utilized as signal transducers in biosensor development.
• Applications include detecting temperature, pH, mechanical stress, and biomolecular interactions.

Purpose of the Study:

• To develop an antibody-based biosensor utilizing PDA liposomes for sensitive detection of human immunoglobulin E (hIgE).
• To enhance the sensitivity of PDA liposome biosensors through the use of gold nanoparticle-conjugated antibodies.

Main Methods:

• Immobilization of hIgE monoclonal antibodies onto PDA liposomes for primary hIgE capture.
• Detection of hIgE via changes in PDA liposome fluorescence.
• Application of gold nanoparticle-conjugated polyclonal antibody probes to amplify the fluorescent signal after primary immune reaction.

Main Results:

• The initial PDA liposome biosensor detected hIgE concentrations below 10 ng/mL.
• The addition of gold nanoparticle-conjugated polyclonal antibodies dramatically increased fluorescence signals.
• The enhanced biosensor achieved a detection limit as low as 0.1 ng/mL, representing a 100-fold sensitivity increase.

Conclusions:

• Gold nanoparticle-conjugated polyclonal antibody probes are highly effective in amplifying fluorescent signals in PDA liposome biosensors.
• This enhanced strategy significantly improves sensitivity for detecting ultra-low protein concentrations.
• The developed biosensor shows promise for sensitive hIgE detection and potentially other protein analytes.