氢离子敏场效应管型尿素传感器及其应用

Miniature Urea Sensor Based on H^+-ion Sensitive Fieid Effect Transistor and Its Application in Clinical Analysis

在H^+-IS FET(离子敏场效应晶体管)的二个栅极表面分别复盖一层戊二醛交联的牛血清清蛋白-脲酶膜及牛血清清蛋白膜即制成差分式尿素-酶FET传感器。该传感器的响应时间小于1min。尿素浓度为1.0—8.0mg/dL时,响应值与尿素浓度对数值呈线性关系,线性相关系数为0.997,响应灵敏度为50mV/dec.(mg/dL)。尿素浓度为0.1—1.0mg/dL时,响应值与尿素浓度呈线性关系,线性相关系数为0.998,响应灵敏度为12—15mV/mg/dL。该传感器对100mg/dL尿素溶液的20次响应的标准偏差及变异系数分别为1.39mV和1.44%。用该尿素-酶FET测定血清样品中的BUN(血中尿素氮)值时,与酶法相比较,两者之间的相关系数为0.9912。该传感器在1个半月内累计使用250次后,响应灵敏度下降约10%。

An urea-ENFET (Enzyme field effect transistor) probe was made by nodifying one gate of the dual ISFET (Ion sensitive field effect transi- stor)with a membrane of cross-linked bovine serum albumin(BSA)-urease and the other With cross-linked BSA, and the response characteristics of the probe was then tested through differential measurement. In different concentration of phosphate buffer, the sensor responded to various con-centrations of urea solution within 10—60 s. From the calibration curve plotted on logarithmic scales a linear concentration range of 1.0—8.0mg/dl was acquied,and the correlation coeffient and response sensitivity were 0.997 and 50mV/dec. (mg/dl) respectively. However,in low concentration urea solution, the sensor responded linearly to urea over the concentra-tion 0.1—1.0mg/dl with a correlation coefficient of 0.998 and a respon-se sensitivity of 12—15mV/dl. The standard deviation and variation coe-fficient for 20 times performances response to 100mg/dl urea in 0.01M