Cholesterol oxidase biosensor based on a glassy carbon electrode modified with Nafion and methyl viologen

<正> Cholesterol oxidase biosensor has been constructed by using bovine serum albumin and glutaraldehyde as cross linker to immobilize cholesterol oxidase and cholesterol esterase on a glassy carbon electrode modified with Nafion and methyl viologen. The biosensor has been used to determine total cholesterol in blood. The linear range of the determination is 2.5×10～7 to 1.0×10-4 mol/L. The detection limit is about 5.0×10～8 mol/L. The response time is 12 s. This biosensor has the advantage of high selectivity, sensitivity and short response time.