Biopolymers and cell. 1996; 12 (4): 25 - 30

A proteolytic biosensor based on a pH-sensititive field effect transistor. 1. Investigation of operation in model solutions

O.A.Beloivan,A.P.Soldatkin,N.F.Starodub,A.V.Ktskaya

The laboratory prototype of biosensor has been fabricated on the basis of trypsin immobilized on the gate surface of pH-sensitive field effect transistor which should be useful for detection of tlie total protein concentration in biological fluids. The optimal conditions to provide marswements have been determined. The characteristics of its operation stability and accuracy in a model system have been obtained. Tlie biosensor prototype can measure concentrations of Na-benzoil-arginin ethyl ester in the range of 0.2-3.0 mM. The effects ofpH, buffer capacity and ionic strength on the response of the biosensor have been investigated. All the results have been discussed in frame of the problem of detecting total protein concentration in biological fluids.