Electrodeposited nanogold decorated graphene modified carbon ionic liquid electrode for the electrochemical myoglobin biosensor
Electrodeposited nanogold decorated graphene modified carbon ionic liquid electrode for the electrochemical myoglobin biosensor
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DOI：
10.1007/s10008-013-2098-z
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发表时间：
2013-08-01
影响因子：
2.5
通讯作者：
Sun, Zhenfan
中科院分区：
文献类型：
--
作者：
Li, Gaonan;Li, Tongtong;Sun, Zhenfan
本文以离子液体六氟磷酸1-己基吡啶盐为修饰剂制备了碳离子液体电极（CILE），并将其与石墨烯（GR）和金纳米粒子分步原位电沉积，得到Au/GR纳米复合修饰的CILE。将肌红蛋白（Mb）进一步用Nafion膜固定在Au/GR/CILE表面，得到Nafion/Mb/Au/GR/CILE修饰电极。循环伏安实验表明，在pH3.0的磷酸盐缓冲溶液中，在-0.197 V（vs.饱和甘汞电极）处出现一对准可逆氧化还原峰，这是Mb血红素Fe（III）/Fe（II）氧化还原电对的典型特征。因此，由于Au/GR纳米复合物存在于电极表面上的高电导率和增加的表面积，促进了Mb与修饰电极之间的直接电子转移速率。基于循环伏安数据，计算了Mb在修饰电极上的电化学参数。该修饰电极对三氯乙酸和H2 O2的还原具有良好的电催化活性，线性范围宽，检测限低。利用GR和Au纳米粒子修饰的CILE，构建了一种新的第三代电化学Mb生物传感器，具有良好的稳定性和重现性。
In this paper, a carbon ionic liquid electrode (CILE) was fabricated using ionic liquid 1-hexylpyridinium hexafluorophosphate as modifier, which was further in situ electrodeposited with graphene (GR) and gold nanoparticles step by step to get an Au/GR nanocomposite modified CILE. Myoglobin (Mb) was further immobilized on the Au/GR/CILE surface with Nafion film to get the modified electrode denoted as Nafion/Mb/Au/GR/CILE. Cyclic voltammetric experiments indicated that a pair of well-defined quasi-reversible redox peaks appeared in pH 3.0 phosphate buffer solution with the formal potential (E (0')) located at -0.197 V (vs. saturated calomel electrode), which was the typical characteristics of Mb heme Fe(III)/Fe(II) redox couples. Thus, the direct electron transfer rate between Mb and the modified electrode was promoted due to the high conductivity and increased surface area of Au/GR nanocomposite present on electrode surface. Based on the cyclic voltammetric data, the electrochemical parameters of Mb on the modified electrode were calculated. The Mb-modified electrode showed excellent electrocatalytic activities towards the reduction of trichloroacetic acid and H2O2 with wider linear range and lower detection limit. Using GR and Au nanoparticles modified CILE, a new third-generation electrochemical Mb biosensor was constructed with good stability and reproducibility.