Flow-through fluoroimmunosensor for isoproturon determination in agricultural foodstuff: Evaluation of antibody immobilization on solid support Original Research Article

A flow-through fluoroimmunosensor for isoproturon determination is described. Two different solid supports (CPG-Prot A binder and CPG) for temporary and permanent antibody immobilization were compared in a direct competitive assay. The highest antibody-hapten binding capacity values were observed when the antibody was directly bonded to CPG-Prot A. The solid support containing the immobilized antibody constituted the immunosensor and was placed in the optical path of a flow cell located in the sample holder of a spectrofluorimeter. The immunoreaction took place in the solid phase and the isoproturon was determined in situ by measuring the immunosensor fluorescence after optimizing the parameters affecting the immunoreaction. The best performance for isoproturon determination was obtained when used antibody permanently immobilized on CPG-Prot A. The immunosensor developed is capable of determining isoproturon at μg l−1 level with negligible cross reactivity of phenylurea-related compounds. The immunosensor has been for the successful applied to determine isoproturon in well water and agricultural foodstuff.