OPTIMAL IMMOBILIZATION OF PENICILLINASE FOR ION-SELECTIVE ELECTRODE

Penicillin sensor was prepared by immobilizing penicillinase (Pcase) o n H+-selective carboxylated poly (vinyl chloride) (PVC-COOH) membrane or cellulose filter membrane. The immobilization techniques are as fol lows. Pcase was immobilized with GTH on H+-selective PVC-COOH membrane or some amount of BSA was dropped on that membrane. Another method to make immobilization is to mix type I Pcase with GTH and drop on a cel lulose filter membrane. According to immobilization techniques, there were some differences in response properties of enzyme electrodes, how ever, all electrodes responded to Pcase-resistant penicillin derivativ es. Pcase immobilized on cellulose filter membrane with H+-selective P VC membrane eletrode was more stable and more sensitive to penicillina se-resistant penicillin derivatives than any other immobilization tech niques.