Core-Shell-Shell Upconversion Nanomaterials Applying for Simultaneous Immunofluorescent Detection of Fenpropathrin...

Area of Science:

• Materials Science: Synthesis and characterization of core-shell-shell upconversion nanoparticles (UCNPs) for enhanced luminescence.
• Analytical Chemistry: Development of a novel fluorescence immunoassay for pesticide detection.

Background:

• Existing methods for pesticide detection can be time-consuming and lack sensitivity for simultaneous analysis.
• Upconversion nanoparticles (UCNPs) offer unique optical properties for sensitive bioassays.
• Fenpropathrin and procymidone are widely used pesticides requiring efficient detection methods.

Purpose of the Study:

• To synthesize novel core-shell-shell UCNPs with improved upconversion luminescence efficiency.
• To establish a rapid and sensitive fluorescence immunoassay for the simultaneous detection of fenpropathrin and procymidone.
• To validate the developed immunoassay for detecting these pesticides in various food matrices.

Main Methods:

• Synthesis of NaGdF4@NaGdF4: Yb, Tm@NaGdF4: Yb, Nd and NaYF4@NaYF4: Yb, Er@NaYF4 UCNPs with core-shell-shell structures.
• Conjugation of UCNPs with antibodies and magnetic nanoparticles with antigens to create signal and capture probes.
• Development of a competitive fluorescence immunoassay utilizing magnetic separation and 980 nm excited luminescence detection.

Main Results:

• The synthesized UCNPs exhibited suppressed fluorescence quenching and enhanced luminescence efficiency.
• The developed immunoassay achieved low detection limits of 0.114 µg/kg for fenpropathrin and 0.082 µg/kg for procymidone.
• The method showed high accuracy with average recovery rates between 85.61% and 102.43% in real food samples (tomatoes, cucumbers, cabbage).

Conclusions:

• The core-shell-shell UCNP-based fluorescence immunoassay is a sensitive, accurate, and rapid method for simultaneous detection of fenpropathrin and procymidone.
• This method is suitable for routine analysis of these pesticides in food products.
• The findings demonstrate the potential of advanced UCNP materials in developing efficient analytical tools for food safety.