the difference between different enzyme membrane prepared with plasma treatment is very small the optimum ph range is from ph 4 5 to 7 5 fig4 the buffer concentration ranging from 0 1m to 0 8m has no influence on the glucose oxidase membrane fig5 the membrane stored in glycerol buffer at 4 u00b0 c for 45 days retains 50 of its original activity as shown in fig6 and the following table table______________________________________time days 1 10 20 25 30 45______________________________________rt dry 100 44 22 20 8 9 6 7rt buffer 100 87 52 35 26 22rt glycerol 100 82 75 48 38 354 u00b0 c dry 100 97 70 28 13 124 u00b0 c buffer 100 96 54 49 47 414 u00b0 c glycerol 100 97 75 60 59 51______________________________________ the membrane can perform 2400 glucose standard tests fig7 and 300 tests of the fermentation broth samples fig8 the glucose oxidase membrane prepared as described above can be used not only as an enzyme electrode in the fermentation industry but also for clinical tests for diabetes and in food processing for sweetness tests it can also be used for the bioconversion of glucose into glutonic acid a hydrophilic polypropylene membrane is cut into a 5 mm id ring the shaped membrane is washed with 0 1m sodium chloride and distilled water dried and stored in a dessicator for later use eight mg of glucose oxidase lactate oxidase from pediococcus species sigma co u s a is dissolved in 1 ml of 0 1m potassium phosphate buffer at ph 7 0 forty mg of bovine serum albumin are dissolved in 1 ml of the same buffer to complete enzyme solution preparation the two solutions are mixed together on each membrane 1.