Gold Nanoparticles Coated With Hydrophobin-ProteinA Fusion Protein: Development of a Versatile Immunosensing Platform

Area of Science:

• Biotechnology and Nanotechnology
• Biosensor Development
• Surface Chemistry

Background:

• Advancements in immunosensing require precise antibody immobilization on transducer surfaces for high sensitivity and selectivity.
• Bioengineered materials offer potential for improved antibody orientation, stability, and performance in biosensors.

Purpose of the Study:

• To develop a novel bioengineered protein for spontaneous and robust antibody attachment on gold nanoparticles (AuNPs).
• To demonstrate the versatility and diagnostic potential of the platform for detecting clinically significant targets.

Main Methods:

• A chimeric protein was created by fusing a hydrophobin (Vmh2) with the Fc-binding region of protein A (SpA).
• This fusion protein self-assembles on AuNPs, creating a bio-interactive layer for antibody immobilization without chemical modification.
• The platform's efficacy was tested using antibodies against fungal laccase, mesothelin, and SARS-CoV-2 spike protein.

Main Results:

• The fusion protein spontaneously adhered to AuNPs, forming a stable layer for antibody attachment.
• The platform demonstrated adaptability and effectiveness in detecting fungal laccase, mesothelin, and SARS-CoV-2.
• A two-step method utilizing induced aggregation of unbound AuNPs was developed for biosensing applications.

Conclusions:

• The developed approach provides a sustainable, versatile, and low-cost method for fabricating biologically active surfaces.
• This technology holds significant promise for applications in medical diagnostics, environmental analysis, and biotechnological innovation.