Enhanced lateral flow immunoassay using gold nanoparticles loaded with enzymes

Area of Science:

• Biotechnology
• Nanotechnology
• Analytical Chemistry

Background:

• Lateral flow immunoassays (LFIA) are widely used for rapid diagnostics.
• Enhancing the sensitivity of LFIA without compromising its simplicity is a key challenge.

Purpose of the Study:

• To develop an improved optical lateral flow immunoassay (LFIA) using gold nanoparticles (AuNPs) and horseradish peroxidase (HRP).
• To investigate strategies for enhancing signal intensity and sensitivity in LFIA.

Main Methods:

• Functionalizing AuNPs with a detection antibody modified with HRP to create an 'enhanced' label.
• Evaluating two detection strategies: direct AuNP color visualization and HRP substrate-mediated color enhancement.
• Assessing the performance with three different HRP substrates.

Main Results:

• The combined AuNP-HRP label significantly enhances LFIA sensitivity, achieving up to a 10-fold increase.
• HRP substrate-based detection provides a darker color, amplifying the signal from the AuNPs.
• The enhanced LFIA maintains the format's inherent simplicity.

Conclusions:

• Combining AuNPs and HRP offers a simple yet effective method to boost LFIA sensitivity.
• This approach allows for on-demand performance tuning of LFIA for various analytical needs.
• The enhanced LFIA opens new possibilities for sensitive and rapid diagnostic applications.