Immobilization of uricase on ZnO nanorods for a reagentless uric acid biosensor

• Published in: Analytica chimica acta Vol. 519; no. 2; pp. 155 - 160
• Main Authors: Zhang, Fenfen, Wang, Xiaoli, Ai, Shiyun, Sun, Zhengdong, Wan, Qiao, Zhu, Ziqiang, Xian, Yuezhong, Jin, Litong, Yamamoto, Katsunobu
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01-08-2004; Elsevier
• Subjects: Biological and medical sciences; Biosensors; Biotechnology; Fundamental and applied biological sciences. Psychology; Methods. Procedures. Technologies; Reagentless biosensor; Uric acid; Uricase; Various methods and equipments; ZnO nanorods; ZnO nanorods; Uric acid; Uricase; Reagentless biosensor; Enzyme; Urate oxidase; Immobilization; Electron transfer; Nanostructure; Chemical sensor; Thermal stability; Electrocatalysis; Biosensor; Detection limit; Zinc oxide; Oxidation; Oxidoreductases
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/j.aca.2004.05.070

A reagentless uric acid (UA) biosensor based on uricase immobilized on ZnO nanorods was developed. Direct electrochemistry and thermal stability of immobilized uricase were studied. The ZnO nanorods derived electrode retained the enzyme bioactivity and could enhance the electron transfer between the enzyme and the electrode. This sensor showed a high thermal stability up to 85
°C and an electrocatalytic activity to the oxidation of uric acid without the presence of an electron mediator. The electrocatalytic response showed a linear dependence on the uric acid concentration ranging from 5.0 × 10
−6 to 1.0 × 10
−3
mol
L
−1 with a detection limit of 2.0 × 10
−6
mol
L
−1 at 3
σ. The apparent
K
M
app value for the uric acid sensor was estimated to be 0.238
mM, showing a high affinity.