Development of a screen-printed cholesterol biosensor: Comparing the performance of gold and platinum as the working electrode material and fabrication using a self-assembly approach

作者：Shen Jie; Liu Chung Chiun^*

来源：Sensors and Actuators B: Chemical , 2007, 120(2): 417-425.

DOI：10.1016/j.snb.2006.02.035

• cholesterol biosensor
• thick film
• screen printing
• cholesterol oxidase

Gold (Au) and platinum (Pt) were used as the working electrode material to detect cholesterol in solution through enzymatically generated hydrogen peroxide (H2O2). Both gold and platinum were capable of detecting cholesterol through the electrochemical oxidation of H2O2, and could be used as the working electrode material. By comparison, however, Au was preferable over Pt in terms of higher response current and better sensitivity. Therefore, Au was chosen as the working electrode material for the fabrication of a thick-film screen-printed cholesterol biosensor consisting of three electrodes on an alumina substrate (working: Au, reference: Ag/AgCl, and counter: Au). The immobilization of the enzyme cholesterol oxidase (ChOx, E.C. 1.1.3.6) on the An working electrode was achieved using a self-assembly approach. A thiol, 3-mercaptopropionic acid (MPA), was self-assembled onto the gold working electrode forming a thin organic layer that served as the anchor for the enzyme immobilization. 1-Ethyl-3 (3-dimethylarni no propyl)carbodiimide methiodide (EDC) was then used to immobilize the enzyme ChOx covalently on the gold working electrode through the carbodiimide coupling between the carboxyl (-COOH) groups of the self-assembled MPA layer and the amino (-NH2) groups of the enzyme. Electrochemical measurements showed that this biosensor responded well to cholesterol, confirming that the self-assembly immobilization method was effective. The reproducibility, the interference, and the storage stability of the biosensor were studied and assessed.

• 出版日期2007-1-10