Highly sensitive atrazine fluorescence immunoassay by using magnetic separation and upconversion nanoparticles as...

Area of Science:

• Analytical Chemistry
• Environmental Science
• Biotechnology

Background:

• Atrazine is a widely used herbicide, and its detection in environmental and food samples is crucial for monitoring and safety.
• Existing detection methods may lack sensitivity, require complex sample preparation, or are time-consuming.
• Development of rapid, sensitive, and selective analytical techniques is essential for effective herbicide monitoring.

Purpose of the Study:

• To establish a high-sensitivity fluorescence immunoassay for the detection of atrazine.
• To utilize hydrophilic upconversion nanoparticles (UCNPs) and magnetic microspheres for enhanced assay performance.
• To enable simultaneous detection of atrazine, propazine, and prometryn in various sample matrices.

Main Methods:

• Conjugation of anti-atrazine antibody to NaYF4:Yb/Er upconversion nanoparticles (UCNPs) as signal probes.
• Conjugation of coating antigen to polystyrene magnetic microspheres (PMMs) as capture probes.
• Competitive immunoassay format with magnetic separation and fluorescence detection at 980/552 nm.

Main Results:

• The immunoassay demonstrated a linear range of 0.005 to 10 μg·L⁻¹ for atrazine.
• Detection limits were as low as 2 ng·L⁻¹ in sugar cane juice/river water and 20 ng·kg⁻¹ in corn/rice.
• Simultaneous detection of atrazine, propazine, and prometryn was achieved, with recoveries ranging from 84.7% to 113.6%.

Conclusions:

• The developed fluorescence immunoassay provides a sensitive and selective method for atrazine detection.
• The combination of UCNPs and magnetic separation allows for efficient analysis with minimal sample pretreatment.
• This assay is suitable for the rapid and simultaneous determination of triazine herbicides in diverse food and environmental samples.