Enhanced Direct Electron Transfer of Fructose Dehydrogenase Rationally Immobilized on a 2-Aminoanthracene Diazonium Cation Grafted Single-Walled Carbon Nanotube Based Electrode
Enhanced Direct Electron Transfer of Fructose Dehydrogenase Rationally Immobilized on a 2-Aminoanthracene Diazonium Cation Grafted Single-Walled Carbon Nanotube Based Electrode
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DOI：
10.1021/acscatal.8b02729
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发表时间：
2018-11-01
期刊：
影响因子：
12.9
通讯作者：
Antiochia, Riccarda
中科院分区：
文献类型：
--
作者：
Bollella, Paolo;Hibino, Yuya;Antiochia, Riccarda
在玻璃碳电极上沉积蒽修饰的单壁碳纳米管，实现了果糖脱氢酶（FDH）与玻璃碳电极的直接电子转移（DET）反应. SWCNT用重氮盐原位活化，所述重氮盐通过2-氨基蒽与NaNO 2在酸性介质（0.5M HCl）中在0 ℃下反应5分钟而合成。在原位反应之后，通过从+1000至-1000 mV运行循环伏安图来电沉积2-氨基蒽重氮盐。将蒽-SWCNT-修饰的GCE进一步在FDH溶液中孵育，允许酶吸附。修饰电极的循环伏安图显示两对氧化还原波，可能归因于细胞色素结构域的血红素c（1）和血红素c（3）。在10 mM果糖存在下，可以清楚地看到两个催化波，并与两个血红素c（血红素c（1）和c（2））相关，在0.4 V和10 mV s（-1）扫描速率下的最大电流密度为485 +/- 21 μ A cm（-2）。相比之下，对于普通SWCNT修饰的GCE，仅观察到一个催化波和一对氧化还原波。FDH直接吸附到GCE上没有表现出FDH的非周转电化学，并且在果糖的存在下，只能看到轻微的催化作用。这些差异可以通过考虑靠近细胞色素结构域的血红素c（1）、血红素c（2）和血红素c（3）的疏水口袋来解释，在所述疏水口袋处蒽基芳香结构可以通过π-π相互作用与FDH的疏水口袋中存在的氨基酸的芳香侧链相互作用。
In this paper, an efficient direct electron transfer (DET) reaction was achieved between fructose dehydrogenase (FDH) and a glassy-carbon electrode (GCE) upon which anthracene-modified single-walled carbon nano tubes were deposited. The SWCNTs were activated in situ with a diazonium salt synthesized through the reaction of 2-aminoanthracene with NaNO2 in acidic media (0.5 M HCl) for 5 min at 0 degrees C. After the in situ reaction, the 2-aminoanthracene diazonium salt was electrodeposited by running cyclic voltammograms from +1000 to -1000 mV. The anthracene-SWCNT-modified GCE was further incubated in an FDH solution, allowing enzyme adsorption. Cyclic voltammograms of the FDH-modified electrode revealed two couples of redox waves possibly ascribed to the heme c(1) and heme c(3) of the cytochrome domain. In the presence of 10 mM fructose two catalytic waves could clearly be seen and were correlated with two heme cs (heme c(1) and c(2)), with a maximum current density of 485 +/- 21 mu A cm(-2) at 0.4 V at a sweep rate of 10 mV s(-1). In contrast, for the plain SWCNT-modified GCE only one catalytic wave and one couple of redox waves were observed. Adsorbing FDH directly onto a GCE showed no non turnover electrochemistry of FDH, and in the presence of fructose only a slight catalytic effect could be seen. These differences can be explained by considering the hydrophobic pocket close to heme c(1), heme c(2) and heme c(3) of the cytochrome domain at which the anthracenyl aromatic structure could interact through pi-pi interactions with the aromatic side chains of the amino acids present in the hydrophobic pocket of FDH.