Biopolymers and cell. 1996; 12 (4): 31 - 37

Development of potentiometric immunosensor for interferon detection

T. A. Sergeyeva, A. P. Soldatkin, A. E. Rachkov, M. I. Tereschenko, S. A. Piletsky, A. V. El`skaya

The effective immunosensor for a^-interferon detection based on ion-sensitive field effect transistor /ias been developed. A specific sensingelement is fabricated by immobilizing interferon on the gate ofpH-sensi-tive field effect transistor (pH-FET). The interaction of anti-interferon antibodies labelled with ft-lac-tamase with. interferon-pH-FET (in the presence of specific enzyme substrate) leads toalocalpH-change and produces electroc/iemical signal which is in proportion to the conjugate concentration. The main work¬ing characteristics of the sensor obtained have been estimated. The competitive electroimmunoassay has been employed for interferon detection in analysed solution. The sensor linear response to interferon con¬centration is obtained in the range 10—200 (fig/mi This gives a possibility of interferon detection in nandiluted cultural medium. The data of the competitive electroimmunoassay are in a good accordance with the ELJSA ones. The possibility of regeneration of the immunosensor obtained has been shown.