Urea biosensor based on immobilization of urease onto self – assembled monolayers

• Main Authors: Yi-Chi Tsai, 蔡逸淇
• Other Authors: Chien-Hsing Hsu
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/a5cu9e

碩士 === 逢甲大學 === 化學工程學所 === 100 === In this study, a sensor device has been developed for detecting urea.3-aminopropyltrimethoxysilane, APTMS, has been coated on titanium dioxide and generated amine group on the surface by using self-assembled technology. Then the titanium dioxide was dipped into a urease solution, which had been activated by premixed EDC/NHS, to form amide bond between urease and amino group on the sensor electrode. Pt-C catalyst was added to the urease solution to make a stronger potential signal. The performances of the enzyme electrodes made from various different conditions were examined and compared. From the experimental results,urease concentration of 40 mg/ml with Pt-C catalyst makes the best enzyme electrode. At T = 20℃、pH = 6 environment, it shows that the sensor has high sensitivity 61.91 mV/decade, response time 95 ~ 195 s, and the linear range is 0.0005 ~ 0.01 M urea. After three weeks the enzyme activity of the biosensor still holds up to 67%.