The use of plasticizers to improve the quality of plastics widely used for household purposes inevitably leads to an increase in their pollution of food and environmental objects. Diisobutyl phthalate (DiBP) is one of the ortho-substituted phthalic acid esters that negatively affect human health and ecosystems. This work is directed to the development of a chemiluminescent enzyme immunoassay (CL-ELISA) for the determination of diisobutyl phthalate in water and food. Luminol, which is oxidized with hydrogen peroxide in the presence of p-iodophenol as an enhancer, was chosen as the substrate for horseradish peroxidase used as a label in the analysis. For this development, rabbit anti-DiBP polyclonal antibodies were generated and tested with the synthesized hapten–protein conjugate. The developed chemiluminescent ELISA has a detection limit of 1.8 ng/mL; the operating range was 5.0–170.8 ng/mL at a content of 10% methanol in the assay medium. The assay was successfully applied to detect diisobutyl phthalate in lettuce leaves, seafood, and water. When using extraction with methanol and hexane, the recovery of DiBP in samples varies in the range of 76.9–134.2%; for assays in natural waters, the recovery rates are from 79.5 to 113.4%.

The use of a large amount of toxic synthetic materials leads to an increase in the pollution of environmental objects. Phthalates are compounds structurally related to esters of phthalic acid that are widely used in the manufacturing of synthetic packaging materials as plasticizers. Their danger is conditioned by leaching into the environment and penetrating into living organisms with negative consequences and effects on various organs and tissues. This work presents the first development of lateral flow immunoassay to detect dibutyl phthalate, one of the most common representatives of the phthalates group. To form a test zone, a hapten–protein conjugate was synthesized, and gold nanoparticles conjugated with antibodies to dibutyl phthalate were used as a detecting conjugate. The work includes the preparation of immunoreagents, selectivity investigation, and the study of the characteristics of the medium providing a reliable optical signal. Under the selected conditions for the analysis, the detection limit was 33.4 ng/mL, and the working range of the determined concentrations was from 42.4 to 1500 ng/mL. Time of the assay–15 min. The developed technique was successfully applied to detect dibutyl phthalate in natural waters with recovery rates from 75 to 115%.

Gold spherical nanoparticles, gold-platinum nanoflowers, and gold-silver nanostars were obtained and compared as labels for immunochromatographic analysis. The nanoparticles were synthesized by chemical reduction from various precursors and then conjugated with staphylococcal protein A to be used in indirect immunochromatographic determination of nonylphenol. The results obtained were evaluated in terms of analytical characteristics and R2 value, as well as the color intensity of the test band. According to the comparison results, it was revealed that the R2 value varied from 0.82 for the gold-silver nanostars to 0.96 for the spherical gold nanoparticles. The working range of determined concentrations was from 2 to 100 μg/mL for unspherical and from 2 to 50 μg/mL – for spherical markers used; the analysis time was 20 min.

Series of preparations of nanoparticles of various shapes, compositions, and surface patterns have been obtained. All preparations are conjugated with staphylococcal protein A by physical adsorption and tested in an indirect scheme for the immunochromatographic determination of nonylphenol, a non-ionic surfactant, a significant technogenic toxic environmental contaminant.