From Hapten Design to Mechanism Exploration: Developing a High-Specificity Immunochromatography Strip for Fluridone...

Area of Science:

• Environmental Chemistry
• Analytical Chemistry
• Biotechnology

Background:

• Fluridone (FLU) is an aquatic herbicide with potential risks to ecosystems and food safety due to improper use and residues.
• Sensitive and reliable detection methods are essential for monitoring FLU contamination.

Purpose of the Study:

• To develop novel fluridone (FLU) haptens and a high-affinity monoclonal antibody (mAb-2B2).
• To establish a rapid and sensitive gold nanoparticles-immunochromatographic strip (GNPs-ICS) method for detecting FLU residues.

Main Methods:

• Rational design of FLU haptens and selection via computer-aided simulations.
• Production of a specific monoclonal antibody (mAb-2B2) through mouse immunization and cell fusion.
• Development of a gold nanoparticles-immunochromatographic strip (GNPs-ICS) assay.

Main Results:

• A high-affinity antibody (mAb-2B2) with a K_a of 3.72 × 10⁹ L/mol and IC₅₀ of 0.50 ng/mL was generated, showing minimal cross-reactivity.
• Molecular docking identified key amino acid residues (ARG 99, ARG 96, ARG 100, TYR 91) responsible for specific antibody recognition.
• The developed GNPs-ICS method achieved detection ranges of 4.22-31.55 ng/mL (river water), 13.61-65.01 μg/kg (crayfish), and 5.51-35.40 μg/kg (fish).

Conclusions:

• The novel mAb-2B2 exhibits high affinity and specificity for fluridone detection.
• The established GNPs-ICS method provides a rapid and effective tool for the primary screening of FLU residues in environmental and aquatic product samples.