Immobilized enzyme membrane for a semiconductor sensor

A method for producing a membrane containing an immobilized enzyme comprising the steps of:

• coating on a base an aqueous solution which is composed of a water soluble photosensitive resin including polyvinyl pyrrolidone having a high molecular weight and 2,5-bis(4'-azide-2'-sulfobenzal) cyclopentanone sodium salt, and an enzyme;
• drying the aqueous solution thus coated on said base so as to form a membrane containing an immobilized enzyme;
• and
• irradiating said membrane containing an immobilized enzyme with ultraviolet light to provide photo-crosslinking between said polyvinyl pyrrolidone, said cyclopentanone sodium salt, and said enzyme.

A sensor containing an enzyme comprising:

• a first pH-ion sensitive field effect transistor having a membrane containing a first immobilized enzyme, said membrane being composed of a first water soluble photosensitive resin including polyvinyl pyrrolidone having a high molecular weight crosslinked to 2,5-bis(4'-azide-2'-sulfobenzal) cyclopentanone sodium salt, and said first enzyme;
• a second pH-ion sensitive field effect transistor;
• and
• a reference electrode.