Wang Z X, Li S Y, Zhong L C, Li G X
Institute of Semiconductors, Chinese Academy of Sciences, Beijing.
Chin J Biotechnol. 1990;6(2):149-56.
Enzyme FET (Field effect transister) is a kind of new device developed recently, which is made through the combination of semiconductor and biological technology. Enzyme FET with differential output can provide automatic compensation for some external factors, e.g. variations of temperature and pH in bulk solution. By using differential measurement, drift of the output voltage with decreased time, and the sensor being miniaturized through the use of "pseudo-reference electrode". Differential model penicillin-ENFET was constructed by modifying one of the dual ISFET gate with a membrane of cross-linked bovine serum albumin (BSA)-penicillinase and the other with a membrane of cross-linked BSA. It responded linearly to penicillin in 0.01M and 0.02M phosphate buffer with sensitivities of 6.5-7.0mV/mM and 3.2-3.6mV/mM over the concentration ranges of 0.5-14mM and 0.5-25mM, respectively. When immersed in 0.01M phosphate buffer and stored in 4 degrees C, this detector had a life time of over 6 months with only a slight decline of output. Accumulative total usage times of the detector could be over one thousand. Finally, the practical applications of differential model penicillin-ENFET in assaying penicillin concentration of fermentation broth are concerned.
酶场效应晶体管（FET）是近年来开发的一种新型器件，它是通过半导体技术与生物技术相结合制成的。具有差分输出的酶FET可以对一些外部因素进行自动补偿，例如本体溶液中温度和pH值的变化。通过采用差分测量，输出电压随时间的漂移得以减小，并且通过使用“伪参比电极”实现了传感器的小型化。差分模型青霉素酶场效应晶体管（penicillin-ENFET）是通过用交联牛血清白蛋白（BSA）-青霉素酶膜修饰双离子敏感场效应晶体管（ISFET）的一个栅极，并用交联BSA膜修饰另一个栅极构建而成的。在0.01M和0.02M磷酸盐缓冲液中，它对青霉素呈线性响应，在0.5 - 14mM和0.5 - 25mM的浓度范围内，灵敏度分别为6.5 - 7.0mV/mM和3.2 - 3.6mV/mM。当浸入0.01M磷酸盐缓冲液并在4℃下储存时，该检测器的使用寿命超过6个月，输出仅有轻微下降。该检测器的累计总使用次数可达一千次以上。最后，还涉及了差分模型青霉素酶场效应晶体管在测定发酵液中青霉素浓度方面的实际应用。
