Influence of the Compounds Used in Immunochromatographic Test-system on its Analytical Characteristics: Multi-factor Optimization of the System for Aflatoxin B1

Analytical parameters of immunochromatographic test-systems, such as the detection limit and working range, depend on many factors. However, the process of choosing the concentration and composition of reagents applied to test strip membranes, and choosing the membranes themselves has not been systematically described for commercially produced tests or for scientific studies. Here, we present the results of a study to determine how the properties of the test system components, using mycotoxin aflatoxin B1 as an example, affect its analytical performance. A comparison of different membranes used for immunochromatography was performed as well as reagent concentrations and composition of intermolecular conjugates. Optimization of the immunochromatographic system indicated a limit of aflatoxin B1 detection equal to 0.2 ng/mL. The effectiveness of the system in testing plant extracts with minimal (twice) dilution prior to analysis was determined and the final content of methanol in the course of immunoassay was 35%.