Developing Gold Nanoparticles-Conjugated Aflatoxin B1 Antifungal Strips

Area of Science:

• Food safety analysis
• Nanotechnology in diagnostics
• Immunochromatographic assays

Background:

• Aflatoxin B1 (AFB1) is a toxic contaminant in food.
• Point-of-care diagnostic tools require high sensitivity and specificity.
• Gold nanoparticles (AuNPs) offer unique optical properties for biosensing.

Purpose of the Study:

• To develop a rapid and sensitive gold nanoparticle (AuNP) immunochromatographic strip for detecting aflatoxin B1 (AFB1).
• To evaluate the performance of the AuNP-based assay in food samples.
• To compare the assay results with established methods like high-performance liquid chromatography (HPLC).

Main Methods:

• Conjugation of AuNPs with bovine serum albumin (BSA) and AFB1 antibody using the N-hydroxysuccinimide ester method.
• Characterization of the conjugated AuNPs using scanning electron microscopy, UV-Vis spectroscopy, and Zetasizer.
• Development of a lateral flow immunochromatographic strip for AFB1 detection.
• Analysis of food samples (peanuts, corn, rice, bread) using the developed strip and smartphone integration.
• Validation against high-performance liquid chromatography (HPLC).

Main Results:

• The AuNP immunochromatographic strip demonstrated a visible color change (red to purple-blue) for AFB1 detection.
• The assay achieved a detection limit of 2 ng/mL in a 96-well plate and 10 ng/g on the strip.
• Smartphone analysis provided results in 3 seconds with a detection limit of 0.3 ng/g for AFB1.
• Excellent agreement was observed between the AuNP strip and HPLC methods for AFB1 determination in various food samples.

Conclusions:

• The developed AuNP immunochromatographic strip is a rapid, sensitive, and reliable tool for detecting AFB1 in food.
• The assay offers potential for point-of-care testing and on-site food safety monitoring.
• Smartphone integration enhances the accessibility and speed of AFB1 analysis.