Preliminary investigations on a glucose biosensor based on the potentiometric principle

• Published in: Sensors and actuators. B, Chemical Vol. 123; no. 2; pp. 720 - 726
• Main Authors: Liao, Cheng-Wei, Chou, Jung-Chuan, Sun, Tai-Ping, Hsiung, Shen-Kan, Hsieh, Jui-Hsiang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 21.05.2007
• Subjects: 3-Glycidyloxypropyltrimethoxysilane (GPTS); Electron mediator; Glucose oxidase (GOD); Potentiometric biosensor; Tin oxide (SnO 2); Electron mediator; 3-Glycidyloxypropyltrimethoxysilane (GPTS); Tin oxide (SnO 2); Glucose oxidase (GOD); Potentiometric biosensor
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2006.10.006

In this study, an electron mediator and a simple immobilization process are adopted to fabricate a potentiometric glucose biosensor. The enzyme and the electron mediator are immobilized on the surface of tin oxide (SnO 2)/indium tin oxide (ITO) glass using a covalent bond method to develop a disposable potentiometric glucose biosensor. The SnO 2/ITO glass is a pH sensor fabricated by depositing SnO 2 thin films onto an ITO glass. The glucose oxidase (GOD) and the electron mediator (ferrocenecarboxylic acid, FcA) are co-immobilized on the SnO 2/ITO glass using 3-glycidyloxypropyltrimethoxysilane (GPTS). This work investigates the coimmobilization of GOD and FcA as a useful approach for enlarging the dynamic range to a glucose concentration of 360 mg/dl, and for improving linearity and sensitivity of the fabricated glucose biosensor. The experimental results indicate that the optimal weight ratio of GOD to FcA is 1:1. The output signal is associated with the pH of the measurement environment and the optimal pH value is pH 7.5.