电聚合修饰碳纤维电极及乳酸脱氢酶活性的测定

Determination of Lactate Dehydrogenase at a Modified Carbon Fibre Electrode

用电聚合方法将亚甲基绿 (MG)修饰在碳纤维电极 (直径 7μm)上 ,并用该修饰电极测定了乳酸脱氢酶 (LDH)活性。在烟酰胺腺嘌呤二核苷酸 (NAD+ )浓度为 6 .0× 10 - 4mol L ,乳酸浓度为 5 .0× 10 - 3mol/L的pH7.0NaOH KH2 PO4 缓冲介质中 ,电位恒定在 +0 .10V下 ,用电流法测定乳酸脱氢酶活性 ,线性范围为 15～ 2 4 0U/mL ,检测限为 10U/mL ,响应时间为 15s。该修饰微电极稳定性好、灵敏度高。

The cyclic voltammetric electropolymerization of multilayer coatings of the dye methylene green on carbon fibre electrode is reported. The modified carbon fibre electrode was used to the assay of lactate dehydrogenase (LDH). Under the concentration of nicotinamide adenine dinucleotide (NAD(+)) being 6.0 x 10(-4) moI/L, of lactate being 5.0 x 10(-3) moI/L, the modified electrode could detect LDH sensitively at + 0.10 V( vs. SCE) with linear response in the range of 15 U/mL to 240 U/mL. The detection limit was 10 U/mL. Evidence is presented to show the good stability of the modified electrode.