Biosensor containing a biochemical substance immobilized on a layer of olefinic-unsaturated, epoxy functional cross-linked polysiloxane

A biosensor prepared by a method comprising the steps of:

• applying an olefinic-unsaturated, epoxyfunctional polysiloxane to a carrier material in the form of a layer, the polysiloxane having the following structure:
• ##STR7## where the following applies:
• E= ##STR8## Z=a vinyl group or a photopolymerizable group with 8 to 40 C. atoms, which is obtained by addition of a photopolymerizable compound to E, and subsequent addition of an aliphatic, cycloaliphatic or aromatic monoisocyanate or monoisothiocyanate with 2 to 10 C. atoms to the secondary OH group formed upon opening of the epoxide ring,
• R.sup.1 =alkyl with 1 to 4 C. atoms or phenyl,
• R.sup.2 =R.sup.1, E or Z,
• where R.sup.1 and R.sup.2 can be the same or different in each instance,
• x=50 to 1000, y=10 to 300, z=3 to 8,
• cross-linking the polysiloxane by means of high-energy radiation to form an epoxyfunctional cross-linked polysiloxane polymer matrix,
• treating the layer with an aqueous solution of a biochemical substance having groups that covalently react with the epoxy groups of the polysiloxane, whereby the biochemical substance is immobilized in the polymer matrix by reaction with epoxy groups, and
• stabilizing the layer by reaction of any non-reacted epoxy groups remaining after the step of treating with a compound containing an amino group, a carboxyl group or an amino group and a carboxyl group.