ABSTRACT
OBJECTIVE: To study the preparation and characterization of hapten and artificial antigen of dicyclohexyl phthalate. METHODS: A dicyclohexyl phthalate hapten (4-amino dicyclohexyl phthalate) was synthesized by introducing amino as a substituent on the aromatic ring and retaining the ester group, and characterized by 1HNMR, IR and UV. The hapten was conjugated to BSA via amino diazotization linkage. RESULTS: Lambda1 = 214nm, lambda2 = 256nm for the UV of dicyclohexyl 4-nitrophthalate and lambda1 = 226nm, lambda2 = 288nm for the UV of dicyclohexyl 4-aminophthalate. Artificial antigen was prepared and tested by fluorescence, and lambda(ex) = 307nm, lambda(em) = 468nm, and the approximate molar ratio of dicyclohexyl 4-aminophthalate to BSA was 19. The product was used as an immunogen, demonstrating that it is suitable for polyclonal antibody production. CONCLUSION: It is a good method for preparation of artificial antigen of dicyclohexyl phthalate by introducing amino as a substituent on the aromatic ring and retaining the ester group. It was suggested that could supply excellent immune antigen for further preparation of antibody and immunoassay to dicyclohexyl phthalate.
Subject(s)
Antigens/immunology , Phthalic Acids/immunology , Animals , Male , Phthalic Acids/chemical synthesis , RabbitsABSTRACT
A novel, sensitive, and specific competitive fluorescence immunoassay has been developed for the quantitative determination of dibutyl phthalate (DBP) using an antibody-coated plate format. Hapten was synthesized in order to produce polyclonal antibodies against dibutyl phthalate. Polyclonal antisera to dibutyl phthalate were generated in rabbits and used to construct the fluorescence immunoassay for measurement of dibutylphthalate. The assay had a detection limit of about 0.02 microg L(-1), a dynamic range of approximately 0.1-300 microg L(-1). Other similar phthalate compounds do not interfere significantly in the analysis using this immunoassay technique, and the cross-reactivity rates were less than 10%. The study demonstrated that the developed antiserum and fluorescence immunoassay procedure can be used to detect dibutyl phthalate in environmental samples such as tap water, river water, drinking water, and leachate from plastic drinking water bottles.
Subject(s)
Dibutyl Phthalate/analysis , Immunoassay/methods , Animals , Antibodies/chemistry , Antigen-Antibody Reactions , Female , Fluorescence , Haptens/chemistry , Hydrogen-Ion Concentration , Osmolar Concentration , Rabbits , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
ZnS nanoparticles have been prepared and modified with sodium thioglycolate. The functionalized nanoparticles are water-soluble. They were used as fluorescence probes in the determination of proteins, which was proved to be a simple, rapid and specific method. In comparison with single organic fluorophores, these nanoparticle probes are brighter, more stable against photobleaching, and do not suffer from blinking. Under optimum conditions, linear relationships were found between the enhanced intensity of fluorescence at 441 nm and the concentration of protein in the range 0.1-4.0 microg mL(-1) for human serum albumin (HSA), 0.2-3.0 microg mL(-1) for bovine serum albumin (BSA) and 0.1-4.5 microg mL(-1) for gamma-globulin (gamma-G). The limits of detection were 0.015 microg mL(-1) for HSA, 0.024 microg mL(-1) and 0.017 microg mL(-1) for BSA and gamma-G, respectively. The method has been applied to the analysis of human serum samples collected from the hospital and the results were in good agreement with those reported by a hospital, indicating that the method presented here is not only sensitive and simple, but also reliable and suitable for practical application.
