A Disposable Cholesterol Enzyme Biosensor Based on Ferrocene-Capped Gold Nanoparticle Modified Screen-Printed Carbon Electrode

In this paper, a novel amperometric cholesterol biosensor with modified of cholesterol oxidase and cholesterol esterase at ferrocene-capped gold nanoparticle modified screen-printed carbon electrode has been developed. Firstly, the ferrocene-capped gold nanoparticle was synthesized. Then the enzyme ink containing Nafion, cholesterol oxidase, cholesterol esterase and ferrocene-capped gold nanoparticle was dropped into the surface of the screen-printed carbon electrode. The electrocatalytic behavior of cholesterol at cholesterol biosensor was investigated employed electrochemical methods. Under optimized conditions, the catalytic current at cholesterol biosensor exhibited a linear relationship with cholesterol in the range from 50 mu M to 15 mM with a detected limit of 12 mu M at 0.3 V vs Ag/AgCl. Furthermore, the selectivity, specificity and stability of cholesterol sensor was investigated and it was applied to measure the real samples of whole blood, the results was almost same with the data obtained from automatic biochemical analyzer.