Enzyme Activated Gold Nanoparticles for Versatile Site-Selective Bioconjugation.

Area of Science:

• Bioconjugation Chemistry
• Nanotechnology
• Enzymatic Synthesis

Background:

• Gold nanoparticles (AuNPs) are widely used in biomedical applications.
• Efficient and versatile methods for bioconjugating proteins and DNA to AuNPs are crucial for developing advanced nanomaterials.
• Existing bioconjugation techniques can be limited by stability, specificity, or reaction conditions.

Purpose of the Study:

• To develop a new enzymatic method for constructing stable protein- and DNA-gold nanoparticle (AuNP) conjugates.
• To explore the versatility of the method using various functional groups and biomolecules.
• To demonstrate the applicability of the method in constructing complex nanostructures like virus-AuNP conjugates.

Main Methods:

• Functionalization of AuNPs with phenols.
• Enzymatic activation of phenol-AuNPs using tyrosinase.
• Oxidative coupling of activated AuNPs with proteins (proline, thiol, aniline) and DNA.
• Conjugation of AuNPs with biotin and thiol-DNA.
• Construction of tobacco mosaic virus (TMV)-AuNP conjugates.

Main Results:

• A robust and selective enzymatic method for AuNP bioconjugation was established.
• The method successfully conjugated proteins and DNA to AuNPs via diverse functional handles.
• Conjugation was achieved under mild, aqueous conditions within 2 hours.
• Stable TMV-AuNP conjugates were synthesized, demonstrating energy transfer between AuNPs and TMV-bound fluorophores.

Conclusions:

• The enzymatic oxidative coupling strategy provides a facile, site-specific, and efficient route for creating diverse AuNP bioconjugates.
• This method enhances the stability and versatility of AuNP conjugates for applications in nanotechnology and diagnostics.
• The demonstrated energy transfer highlights the potential of these conjugates in advanced optical and sensing applications.