Gold nanorod biochip functionalization by antibody thiolation.

Area of Science:

• Nanotechnology
• Bioconjugation Chemistry
• Biosensor Development

Background:

• Gold nanorod (GNR) functionalization is crucial for biosensing, imaging, and drug delivery.
• Existing methods are complex, involving multiple steps, surfactant exchange, and potential material loss.
• Aggregation and instability are common issues with current GNR functionalization techniques.

Purpose of the Study:

• To develop a facile and robust method for conjugating biomolecules onto GNR surfaces.
• To improve the stability, dispersion, and biofunctionality of GNR-bioconjugates.
• To create a sensitive and specific GNR-based biochip for label-free target detection.

Main Methods:

• Functionalization of GNR surfaces via covalent gold-sulfur (Au-S) bonds by thiolating receptors.
• Assessment of GNR-bioconjugate stability and dispersion in buffer solutions.
• Enzyme-linked immunosorbent assay (ELISA) to confirm biofunctionality.
• Fabrication of a GNR assembly biochip on a glass substrate for target detection.

Main Results:

• The developed method resulted in GNR-bioconjugates with superior dispersion and stability, maintaining integrity for months.
• ELISA confirmed high bioactivity of immobilized thiolated anti-IgG antibodies.
• The GNR biochip demonstrated high sensitivity and specificity for detecting human IgG targets in a label-free manner.
• The method showed a five-fold increase in spectral sensitivity compared to electropolymeric coating.

Conclusions:

• This universal GNR bioconjugation method offers a simple, stable, and efficient alternative to existing techniques.
• The approach enhances GNR performance for biosensing applications, particularly in label-free detection.
• The method is adaptable for various biomolecules, paving the way for advanced biosensors and drug delivery systems.