基于玻碳电极/氧化苏木精/青霉素酶的青霉素电化学传感器

A Novel Electrochemical Sensor for Penicillin with Glassy Carbon Electrode/Hematein/Penicillinase

本文利用青霉素酶与青霉素发生水解反应生成青霉噻唑酸,该酸电离出H+,促使溶液中的氧化苏木精发生还原反应,产生电流信号。以玻碳电极为工作电极,建立一种检测青霉素的电化学方法。在最佳的实验条件下,青霉素浓度在10-9~10-5 mol·L^(-1)范围内与其相对电流强度呈良好的线性关系(r2=0.9973),最低检出限(S/N=3)为1.661×10-8 mol·L^(-1)。连续平行测定1×10-6 mol·L^(-1)的青霉素溶液3次,相对电流强度的RSD为2.50%,表明该方法具有良好的稳定性。将该方法用于牛奶样品的实际测定,回收率为99.70%~102.69%,结果较为理想。

The penicillinase catalyzed the hydrolysis of penicillin to penicilloic acid, which H+ was liberated. H+ promoted the reduction reaction of hematein, thereby generated a current signal. Based on the principle, a new electrochemical method was established for the determination of penicillin at the glass carbon electrode. Under the optimum conditions, the GCE/hematein/penicillinase exhibited excellent performance for penicillin in PBS with a wide range of 10-9~10-5 mol/L and the detect limit was 1.661×10-8 mol/L(S/N=3). The RSD for 1×10-6 mol/L penicillin was 2.50%, which indicated that the method had good stability. The detection of penicillin concentration in real sample (milk) had acceptable accuracy with the assay system, which the recovery was 99.70%~102.69%.