本實驗為利用酵素和非水溶劑的相容性,以Nafion為固定間質(immobilization matrix)的模型,而將酵素固定於白金電極表面,亦即是利用Nafion形成薄膜時將酵素(glucose oxidase,GOD)固定於直徑1.6 mm 的白金電極表面,當葡萄糖存在時,酵素利用氧氣的氧化力將葡萄糖氧化,而生成雙氧水,所以將電極的電位定在+ 650 mV,便可測得在不同葡萄糖濃度所產生的雙氧水的氧化電流。偵測時的條件為0.05M的磷酸/磷酸鹽緩衝溶液,pH=7,當訊號雜音比值為3 (S/N =3)時,此系統的偵測極限為2 X 10^(-6)M。靈敏度為0.795 μA/mM。且此生化感測器對於uric acid(0.2 mM)的干擾低於7%,ascorbic acid (0.2 mM)和cysteine (0.2 mM)的干擾,分別低於5 % 及1%,而galactose (0.2 mM) 和tyrosine (0.2 mM)則對此系統絲毫不產生任何干擾。
The current paper demonstrated the feasibility of utilizing Nafion to immobilize enzyme, Glucose Oxidase. The enzyme was dispersed into a methanol/water mixture and an adequate portion amount of enzyme/polymer solution was casted onto Pt electrode surface. Glucose can be deterrninated at +0.65V with very limited interference (<5%), in the presence of 2.5 X 10^(-4) M ascorbic acid and at the presence of 2.5 X 10^(-4) M cysteine (<1%) and uric acid (<7%). There is no interference at the presence of 2.5 X 10^(-4) M tyrosine and galactose. The linear range of calibration curve is upto 3 X 10^(-3) M and the detection limit is about 2 X 10^(-6) M (S/N =3).