1.8.3.3 3.8 11 enzyme immobilized on microsensor surface out of cellulose acetate 394887 1.8.3.3 5 10 minimal activity below pH 5.0, active at least up to pH 10.0 394884, 394886 1.8.3.3 6.2 8.8 sharp decline in activity below pH 6.2 and above pH 8.8 394886