Macroporous indium tin oxide electrode layers as conducting substrates for immobilization of bulky electroactive guests
Macroporous indium tin oxide electrode layers as conducting substrates for immobilization of bulky electroactive guests
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DOI：
10.1016/j.electacta.2014.05.046
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发表时间：
2014-09-10
影响因子：
6.6
通讯作者：
Fattakhova-Rohlfing, Dina
中科院分区：
文献类型：
--
作者：
Liu, Yujing;Peters, Kristina;Fattakhova-Rohlfing, Dina
采用超小氢氧化铟锡纳米颗粒与聚甲基丙烯酸甲酯(PMMA)微珠直接共组装的方法制备了孔径均匀的大孔氧化铟锡电极。使用纳米ItoH纳米颗粒可以方便地大规模制备均匀的无裂纹涂层，具有良好的附着力、良好的光学质量和可调的厚度，在400℃时很容易转变为具有类似形貌的晶态ITO。大孔ITO薄膜具有较高的电导率(4·0+/-0·3 S cm(-1))和均匀尺寸约为30 0 nm的开放的连通孔，这使其成为固定大量氧化还原物种或沉积功能电活性层的理想导电平台。在多孔ITO支架的壁上沉积了功能半导体层，通过横截面的透射电子显微镜分析表明，二氧化钛穿透了ITO骨架。得到的膜被用作固定血红素蛋白细胞色素c和血红蛋白的导电底物，这表明直接电子转移到大孔ITO电极上。细胞色素c吸附在大孔ITO电极上的表面覆盖率是平面ITO电极的12倍以上，对于约360 nm厚的薄膜，其表面覆盖率达到400pmol cm(-2)。吸附在大孔ITO电极上的血红蛋白也显示出显著的高表面覆盖率，约为160+/-20pmol cm(-2)，这大约是单层覆盖率理论值的7-10倍。(C)2014爱思唯尔有限公司。保留所有权利。
Macroporous indium tin oxide (ITO) electrodes with a defined uniform pore size were prepared via direct co-assembly of ultra-small indium tin hydroxide (nano-ITOH) nanoparticles and poly(methyl methacrylate) (PMMA) beads. The use of nano-ITOH nanoparticles enables a facile large-scale fabrication of homogeneous crack-free coatings with good adhesion to the substrate, good optical quality and tunable thickness, which easily transform at 400 degrees C into crystalline ITO with similar morphology. Macroporous ITO films exhibit reasonably high electric conductivity of 4.0 +/- 0.3 S cm(-1) and open interconnected pores with a uniform size of ca. 300 nm, which makes them suitable conducting platforms for immobilization of bulky redox species or for deposition of functional electroactive layers. Deposition of functional semiconducting layers on the walls of the porous ITO scaffold was shown for titanium dioxide, which penetrates the ITO framework as shown by transmission electron microscopy (TEM) analysis of a cross-section. The obtained layers were used as conducting substrates for the immobilization of the heme proteins cytochrome c and hemoglobin, which demonstrate a direct electron transfer to the macroporous ITO electrode. Surface coverage of cytochrome c adsorbed on the macroporous ITO electrode is more than 12 times higher than on a planar one, reaching 400 pmol cm(-2) for a film of ca. 360 nm in thickness. Hemoglobin adsorbed on the macroporous ITO electrodes also demonstrates a noticeably high surface coverage of ca. 160 +/- 20 pmol cm(-2), which is roughly 7-10 times higher than the theoretical value for monolayer coverage. (C) 2014 Elsevier Ltd. All rights reserved.