Evaluation of antibody immobilization methods for piezoelectric biosensor application

Area of Science:

• Biosensor technology
• Immunochemistry
• Surface science

Background:

• Developing sensitive and reproducible biosensors for pathogen detection is crucial.
• Antibody immobilization is a key step in biosensor fabrication.
• Evaluating different immobilization strategies impacts sensor performance.

Purpose of the Study:

• To compare two antibody immobilization methods for piezoelectric biosensors targeting Salmonella.
• To optimize temperature-time conditions for antibody immobilization.
• To assess the stability, reproducibility, and functionality of immobilized antibodies.

Main Methods:

• Immobilization of anti-Salmonella antibodies using Protein A and glutaraldehyde (GA)/polyethylenimine (PEI) methods.
• Optimization of temperature-time parameters for maximum immobilization yield.
• Fabrication and testing of piezoelectric biosensor probes.
• Dry and wet assay measurements of frequency changes.

Main Results:

• Protein A method achieved 42.1% antibody immobilization, while PEI-GA yielded 31.6%.
• Protein A method demonstrated better reproducibility and less mass addition in dry assays.
• Both methods showed comparable Salmonella binding activity, but Protein A offered enhanced stability.

Conclusions:

• The Protein A method is favorable for immobilizing anti-Salmonella antibodies in piezoelectric biosensors due to superior stability and reproducibility.
• Both immobilization techniques showed functional antibody activity for Salmonella detection.
• Further optimization may be needed to align experimental data with theoretical models like the Sauerbrey equation.