Nafion膜固定血红蛋白和银纳米粒子构筑生物传感器

2010-07-16 11:07李艳彩莫韬
关键词:缓冲溶液电催化伏安

李艳彩,莫韬



李艳彩,莫韬

(漳州师范学院 化学与环境科学系,福建 漳州 363000)

1 实验部分

1.1 试剂

1.2 仪器设备及测试方法

1.3 Hb/AgNPs/Nafion膜电极的制备

2 结果与讨论

2.1 Hb在膜上的直接电子转移

图1 不同膜电极在0.1 mol/L pH值6.9的PBS缓冲溶液中 的循环伏安曲线,扫速为100mV/s

图2是Hb/AgNPs/Nafion膜电极在不同扫速下的循环伏安曲线. 随着扫速的增大,Hb直接电子传递的阴极峰和阳极峰电位变化很小,说明该过程的电子传递速度较快. 由图3可知:扫速范围20~600mV/s,氧化峰和还原峰电流均与扫速成线性关系,这说明电极表面的氧化还原反应是由表面控制的过程,电活性质点在没有物质传递控制下实现转化. 电位负向扫描时,膜中电活性[HbFe(III)]被还原成了[HbFe(II)];电位正向扫描时,膜中电活性[HbFe(II)]被氧化成了[HbFe(III)].

图2 不同扫速下,Hb/AgNPs/Nafion膜电极在0.1 mol/LpH值6.9的PBS缓冲溶液中的循环伏安曲线

图3 阴极峰电流和阳极峰电流与扫速的关系

图4 pH值对Hb/AgNPs/Nafion膜电极电位的影响(扫速100 mv/s)

2.2 pH值对电极电位的影响

图5 扫速100 mv/s,不同膜电极对的电催化还原(pH值4.5的HAc缓冲溶液)

图6 0.1 mol/L不同pH值的HAc缓冲溶液中,Hb/AgNPs/Nafion膜电极的循环伏安曲线(2 NO 浓度为6.0 mmol/L,扫速为100 mV/s)

2.3 Hb/AgNPs/Nafion膜电极对的电催化还原

图7 浓度对Hb/AgNPs/Nafion膜电极的 影响(pH=4.5的HAc缓冲溶液)

图8 10 mL 0.05 mol/LpH=4.5的HAc缓冲溶液中, Hb/AgNPs/Nafion膜电极对催化电流随1时间变化的响应曲线

2.4 Hb/AgNPs/Nafion膜电极的稳定性和选择性

3 结论

[1] TERMIN A, HOFFMANN M, BING R J, A simplified method for the determination of nitric oxide in biological solutions[J]. Life Sci, 1992, 51: 1621-1629.

[2] LIU Songqin, JU Huangxian. Renewable reagentless hydrogen peroxide sensor based on direct electron transfer of horseradish peroxidase immobilized on colloidal gold-modified electrode[J]. Anal Biochem, 2002, 307: 110-116.

[3] YANG Weiwei, BAI Yu, LI Yancai, et al. Amperometric nitrite sensor based on hemoglobin/colloidal gold nanoparticles immobilized on a glassy carbon electrode by a titania sol-gel film[J]. Anal Bioanal Chem, 2005, 382: 44-50.

[4] LIU Songqin, YU Jiuhong, JU Huangxian. Renewable phenol biosensor based on tyrosinase-colloidal gold modified carbon paste electrode[J]. J Electroanal Chem, 2003, 540: 61-67.

[5] LIU Haiying, DENG Jiaqi. An amperometric lactate sensor employing tetrathiafulvalene in nafion film as electron shuttle[J]. Electrochim Acta, 1995, 40: 1845-1849.

[6] SANCHEZ-PANIAGUA LOPEZB M, MECERREYESE D, LOPEZ-CABARCOSB E, et al. Amperometric glucose biosensor based on polymerized ionic liquid microparticles[J]. Biosens Bioelectron, 2006, 21: 2320-2328.

[7] CHEN Hongjun, WANG Yuling, LIU Ying, et al. Direct electrochemistry and electrocatalysis of horseradish peroxidase immobilized in Nafion-RTIL composite film[J]. Electrochem Commun, 2007, 9: 469-474.

[8] LU Yingxi, WANG Qifeng, SUN Junqi, et al. Selective dissolution of the silver component in colloidal Au and Ag multilayers: a facile way to prepare nanoporous gold film materials[J]. Langmuir, 2005, 21: 5179-5184.

[9] BOND A M. Modern polarographic methods in analytical chemistry[M]. New York: Marcel Dekker, 1980.

[10]LIU Songqin, JU Huangxian. Nitrite reduction and detection at a carbon paste electrode containing hemoglobin and colloi dal gold[J]. Analyst, 2003, 128: 1420-1424.

[责任编辑:熊玉涛]

Building Biosensors by Immobilizing Hemoglobin and Silver Nanoparticles and Using Nafion Membrane

LIYan-cai,MOTao

(Chemistry and Environmental Science Department, Zhangzhou Teachers College,

Hemoglobin (Hb) and silver nanoparticles (AgNPs) are immobilized to the surface of glassy carbon electrode by using Nafion membrane. Cyclic voltammetry experiments show that Hb/AgNPs/ Nafion film electrode in pH 6.9 PBS buffer solution has a pair of significant HbFe (Ⅲ)/(Ⅱ) oxide reduction peak and has a good catalytic response to of nitrite. The linear range is 2.0×10-5-3.4×10-4mol/L (=18,=0.997) and the detection limit is 1.2×10-6mol/L (=3). Therefore, the membrane electrode can be used as nitrite biosensor.

1006-7302(2010)03-0006-14

O657.1

A

2010-03-25

福建省教育厅科技项目(JA09163);漳州师范学院科研基金资助项目(L20779)

李艳彩(1980—)女,河南省叶县人,讲师,博士,主要从事电分析化学研究,E-mail: liyancai2000@yahoo.com.cn.

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