A General Approach To Study the Thermodynamics of Ligand Adsorption to Colloidal Surfaces Demonstrated by Means of Catechols Binding to Zinc Oxide Quantum Dots
A General Approach To Study the Thermodynamics of Ligand Adsorption to Colloidal Surfaces Demonstrated by Means of Catechols Binding to Zinc Oxide Quantum Dots
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DOI：
10.1021/cm504080d
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发表时间：
2015-01
影响因子：
8.6
通讯作者：
Wei Lin;J. Walter;A. Burger;H. Maid;A. Hirsch;W. Peukert;D. Segets
中科院分区：
文献类型：
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作者：
Wei Lin;J. Walter;A. Burger;H. Maid;A. Hirsch;W. Peukert;D. Segets
建立了研究配体在胶体表面吸附热力学的一般策略。我们的方法的多功能性证明通过邻苯二酚结合到ZnO量子点（QD）。首先，等温滴定量热法（ITC）被用来提取所有相关的热力学参数，即缔合常数，焓，熵，配体结合的自由能。值得注意的是，测得的ΔG为−20.3 ± 0.4 kJ mol-1，表明邻苯二酚锚基团与氧化物颗粒表面之间存在强烈的、可重复的放热相互作用。为了通过测量吸附热确认配体结合的表征，通过基于质量的吸附等温线交叉验证自由能。开发了电感耦合等离子体发射光谱法（ICP-OES）和UV/维斯光谱法的组合，以定量测定结合儿茶酚相对于可用颗粒表面的质量。结合常数K由Langmuir方程确定。
A general strategy to study the thermodynamics of ligand adsorption to colloidal surfaces was established. The versatility of our approach is demonstrated by means of catechols binding to ZnO quantum dots (QDs). First, isothermal titration calorimetry (ITC) was used to extract all relevant thermodynamic parameters, namely association constant, enthalpy, entropy, and free energy of ligand binding. Noteworthy, the determined ΔG of −20.3 ± 0.4 kJ mol–1 indicates a strong, reproducible, and exothermic interaction between the catechol anchor group and the oxide particle surface. To confirm the characterization of ligand binding by measuring the heat of adsorption, the free energy was cross-validated by mass-based adsorption isotherms. A combination of inductively coupled plasma optical emission spectroscopy (ICP-OES) and UV/vis spectroscopy was developed to quantitatively determine the mass of bound catechols with respect to the available particle surface. The association constant K was determined by a Langmui...