"External" antibodies as the simplest tool for sensitive immunochromatographic tests

Area of Science:

• Analytical Chemistry
• Biochemistry

Background:

• Immunochromatographic assays are widely used for rapid detection of various analytes.
• Traditional competitive assays often face limitations in optimizing antibody and marker concentrations independently, potentially affecting sensitivity.

Purpose of the Study:

• To introduce a novel immunochromatographic competitive analysis scheme using "external" specific antibodies.
• To enhance the sensitivity and detection limits of immunochromatographic tests.

Main Methods:

• Development of a test strip incorporating membranes, antigen conjugates, and colored nanoparticles.
• Utilizing "external" specific antibodies, which are added to the sample dilution buffer, allowing for independent concentration adjustments.
• Pre-incubation of antibodies with the sample during routine dilution.

Main Results:

• The proposed scheme demonstrated high effectiveness for determining deoxynivalenol and T-2 toxin.
• Achieved detection limits of 500 pg/mL for deoxynivalenol and 50 pg/mL for T-2 toxin.
• These limits are an order of magnitude lower than those of traditional tests using identical reagents.

Conclusions:

• The novel assay design allows for independent optimization of antibody and marker concentrations, leading to increased test sensitivity.
• The approach is universal and applicable for detecting a wide range of compounds, offering a significant advancement in analytical methods.