高选择性的镍基无酶葡萄糖微传感器的研制及应用

Novel Enzymeless Glucose Sensor Based on Overoxidized Polypyrrole Modified Nickel Microelectrode

采用电刻蚀法制得微镍电极,通过循环伏安法在微镍电极上修饰过氧化聚吡咯膜,利用葡萄糖在碱性条件下在该修饰电极上的电催化氧化性质,制备了新型的抗干扰的无酶葡萄糖微传感器;研究了其电化学氧化机理,在较低的碱性(pH=12.0)和较低的氧化电位(+0.47V)条件下,微镍修饰电极上产生的Ni(Ⅲ)能直接将葡萄糖氧化为葡萄糖酸内酯,产生的安培响应与葡萄糖浓度在5.0×10-6～1.1×10-3mol/L范围内呈线性关系;检出限为2.4×10-6mol/L。该微传感器灵敏度高(30.4nA/μM)、选择性好(20倍AA和UA不干扰)、响应快(小于3s)、重现性好,而且制作简单、使用方便,已用于流动注射分析(FIA)测定血清中血糖含量。

A novel enzymeless glucose sensor based on overoxidized polypyrrole （oPPy） modified on a self- made nickel mieroeleetrode has been fabricated. The eleetroeatalytie oxidation of glucose in alkaline medium directly at the modified mieroeleetrode has been investigated and which shows excellent eleetroeatalytie activity towards glucose oxidation at low positive potential of 0. 47 V （vs. Ag/AgCl, saturated with KCl） and relative alkaleseenee solution of pH 12. Glucose was determined ehronoamperometrieally at the surface of the modified disk-mieroeleetrode in 0. 01 mol/L NaOH solution. Under the optimized condition, the calibration curve is linear in the concentration range of 5.0 ×10^-6 - 1.1 ×10^-3 mol/L with a detection limit of （S/N = 3 ） 2.4 ×10^-6 moL/L and sensitivity of 30.4 nA（μmoL/L） -1, respectively. The glucose sensor has short response time （ within 3 s） and ean be renewed easily in a reproducible manner by a simple polishing step. In addition, the capabilities of anti-interference and application for direct glucose quantitative analysis by means of FIA in human blood serum are also discussed.