Competitive immunological detection of progesterone by means of the ion-step induced response of an immunoFET

Richardus B.M. Schasfoort, C.E.J.M. Keldermans, R.P.H. Kooyman, Piet Bergveld, Jan Greve

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The ion-step method was originally designed to measure immunoreactions via the change in charge density which occurs in an antibody loaded membrane, deposited on an ISFET, upon reaction with a charged antigen. In this paper we show the possibility of detecting an immunoreaction involving a non-charged antigen, progesterone, by using competitive binding of progesterone and a charged progesterone-lysozyme conjugate in the membrane. Both the immunoreaction and the non-specific binding could unequivocally be measured. The detection limit was approximately 10−8 M of progesterone in the sample solution. This proves that the ion-step method is suitable for detection of both charged and non-charged antigens.
Original languageUndefined
Pages (from-to)368-372
Number of pages5
JournalSensors and actuators. B: Chemical
Issue number1-6
Publication statusPublished - 1990


  • METIS-129414
  • IR-72673

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