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

A flow-through fluoroimmunosensor for isoproturon determination is describe d. Two different solid supports (CPG-Prot A binder and CPG) for temporary a nd permanent antibody immobilization were compared in a direct competitive assay. The highest antibody-hapten binding capacity values were observed wh en the antibody was directly bonded to CPG-Prot A. The solid support contai ning the immobilized antibody constituted the immunosensor and was placed i n the optical path of a flow cell located in the sample holder of a spectro fluorimeter. The immunoreaction took place in the solid phase and the isopr oturon was determined in situ by measuring the immunosensor fluorescence af ter optimizing the parameters affecting the immunoreaction. The best perfor mance for isoproturon determination was obtained when used antibody permane ntly immobilized on CPG-Prot A. The immunosensor developed is capable of de termining isoproturon at mu gl(-1) level with negligible cross reactivity o f phenylurea-related compounds. The immunosensor has been for the successfu l applied to determine isoproturon in well water and agricultural foodstuff . (C) 2000 Elsevier Science B.V. All rights reserved.