Immunoassay for the detection of lead ions in environmental water samples

A rapid, simple, and reliable competitive immunoassay was developed for measurement of lead ions Pb(II) in environmental samples. Avian antibodies were produced against Pb(II). Since lead ions are too small to elicit an immune response, the metal was coupled to protein carrier Bovine serum albumin (BSA) using a bifunctional chelator 1-(4-isothiocyanobenzyl) ethylenediamine N,N,N′,N′-tetra acetic acid (ITCBE). Poultry birds (layers) were immunised with this Pb(II)–ITCBE–BSA immunoconjugate and the avian antibodies (IgY) isolated from egg yolk recognised Pb(II)-ITCBE complexes as capture reagent and a Pb(II)–ITCBE conjugate of Alkaline phosphatase as an enzyme label. Antibody reaction was optimised for different concentrations of antigen and antibody dilutions. Cross reactivity with other metals were below 1% in competitive ELISA. The IC₅₀ value of this avian antibody was 0.19?µg?mL^?1. The detection range and the detection limit were 0.02–1000?µg?mL^?1and 0.2?µg?mL^?1, respectively.