[A novel use of cholinesterase amperometric biosensor for selective determination of 2,4-dichlorophenoxyacetic acid]. / Novyi variant ispol'zovaniia kholinésteraznogo amperometricheskogo biosensora dlia selektivnogo opredeleniia 2,4-dikhlorfenoksiuksusnoi kisloty.

A new method of detection of 2,4-dichlorophenoxyacetic acid by means of immobilized monoclonal antibodies and an amperometric cholinesterase biosensor is proposed. A combination of monoclonal antibodies to 2,4-dichlorophenoxyacetic acid with an enzyme electrode provides high selectivity of measurements and allows trace amounts of this pesticide to be detected within a concentration range of 1 x 10(-1) to 5 x 10(-7) M with a sensitivity threshold of 5 x 10(-12) M.

New variants of enzyme immunoassay of antibodies to DNA.

A method of DNA immobilization on cellulose nitrate films has been developed. Modified films of uniform and stable surface have been used to devise two variants of solid-phase enzyme immunoassays of antibodies. The co-immobilization of enzyme label (cholinesterase) and the DNA molecules makes it possible to carry out the procedure of solid-phase enzyme immunoassay without any separation of components. Thus, it takes only 15 min to diagnose an autoimmune disease (Aleutian disease of minks) with the immunoenzyme amperometric sensor, with a lower detection limit for antibodies of 0.5 x 10(-10) M. For scaled diagnosing, solid-phase enzyme immunoassay on DNA-modified films with prior separation of components and spectrophotometric registration of peroxidase activity has been developed. The time for determination was 30 min, with a lower detection limit of 7.4 x 10(-12) M.