Sol−Gel Matrixes Doped with Atrazine Antibodies:  Atrazine Binding Properties

Sol−gel materials with antibody properties are described. These were constructed by the entrapment of monoclonal anti-atrazine antibodies (Mabs) in SiO2 sol−gel derived matrixes, which successfully recognized and bound atrazine, a widely used herbicide. The binding properties for atrazine were evaluated by comparing sol−gel entrapped anti-atrazine hybridoma culture fluids with entrapped purified immunoglobulins (IgGs). In the study, 14C-labeled and unlabeled atrazine, which are stable to hydrolysis or to other chemical decay processes, were used as analytes. Leaching of the antibodies was found to be zero. Stability was tested under various storage conditions and was found to be 100% for at least 2 months at room temperature, compared with a drop of 40% in solution. The response time was found not to differ considerably from that obtained in solution. Other factors tested included reproducibility of binding, dose response, nonspecific physisorption of atrazine to the ceramic matrix, and elution recoveries of atrazine from the doped sol−gel columns. An advantage of the sol−gel methodology is the elimination of the need to purify the IgGs from the Mab hybridoma culture fluids.