Permeability and Dynamics of a Monolayer are Mediated by ITO Support Surface-Modification
Permeability and Dynamics of a Monolayer are Mediated by ITO Support Surface-Modification
复制标题
单分子层的渗透性和动力学由 ITO 支持表面改性调节
DOI：
10.1021/acs.jpcb.3c02803
复制
发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Blanchard, G. J.
Diana
中科院分区：
文献类型：
--
作者：
Sadeghzadeh, Homa;Nazario Torres, Diana K.;Blanchard, G. J.
Diana
氧化铟锡（ITO）已被广泛用作透明导体。ITO的表面化学反应与用于修饰二氧化硅的反应类似，但长期存在的问题是理解ITO表面修饰的密度和鲁棒性。我们报告了在朗缪尔槽上形成的化学结合的Cd 2+络合十八烷基膦酸（ODPA）单层的形成，并使用朗缪尔-布洛杰特（LB）方法沉积到ITO表面上，无论是以其天然形式还是用膦酸酯官能化（RPO 32-）。的Langmuir单层的组织取决于pH值和存在的Cd 2+在其上形成的水亚相和功能化的ITO表面上。我们探测所得LB-支持界面的渗透性电化学和运动的自由度特性的生色团包含在单分子层使用荧光恢复后光漂白（FRAP）。我们的数据表明，没有修改的ITO表面的单层是显着的渗透所使用的benzores（二茂铁和Ru 3+），和表面改性，以产生共价结合的膦酸酯功能的结果在一个单层，是不可渗透的benzores。FRAP研究揭示了一个相对刚性的单层脂肪链区域沉积在原生或改性的ITO，这表明直接镉+-ITO相互作用。
Indium tin oxide (ITO) has been extensively used as a transparent conductor. The surface chemistry of ITO is amenable to reactions similar to those used to modify silica, but a long-standing issue has been understanding the density and robustness of the ITO surface-modification. We report on the formation of chemically bound Cd2+-complexed octadecylphosphonic acid (ODPA) monolayer formed on a Langmuir trough and deposited using Langmuir–Blodgett (LB) methodology onto an ITO surface, either in its native form or functionalized with phosphonate (RPO32–). The organization of the Langmuir monolayer depends on the pH and presence of Cd2+in the aqueous subphase on which it is formed and on the functionalization of the ITO surface. We probe the permeability of the resulting LB–support interface electrochemically and the motional freedom characteristic of chromophores contained within the monolayer using fluorescence recovery after photobleaching (FRAP). Our data demonstrate that without modification of the ITO surface the monolayer is significantly permeable by the electrophores used (ferrocene and Ru3+), and surface modification to produce covalently bound phosphonate functionality results in a monolayer that is impermeable to the electrophores. FRAP studies reveal a relatively rigid monolayer aliphatic chain region for deposition on either native or modified ITO, suggesting direct Cd2+–ITO interactions.