Vilnius University, Faculty of Chemistry and Geosciences, Institute of Chemistry, Department of Physical Chemistry, Naugarduko str. 24, LT-03225, Vilnius, Lithuania.
Vilnius University, Faculty of Chemistry and Geosciences, Institute of Chemistry, Department of Physical Chemistry, Naugarduko str. 24, LT-03225, Vilnius, Lithuania; NanoTechnas - Center of Nanotechnology and Materials Science at Vilnius University, Faculty of Chemistry and Geosciences, Naugarduko str. 24, LT-03225, Vilnius, Lithuania; State Research Institute Centre for Physical Sciences and Technology, Department of Functional Materials and Electronics, Sauletekio ave. 3, Vilnius, Lithuania.
Talanta. 2020 Dec 1;220:121414. doi: 10.1016/j.talanta.2020.121414. Epub 2020 Jul 18.
Uric acid-imprinted polypyrrole-based (MIP-Ppy) electrochemical quartz crystal microbalance sensor (EQCM) was developed. Experiments and theoretical calculations were focused on molecular interactions between uric acid molecule and: i) polypyrrole imprinted by uric acid (MIP-Ppy) ii) polypyrrole film without any molecular imprints (NIP-Ppy). Resonant frequency differences during electrochemical deposition of MIP-Ppy and NIP-Ppy films were observed and were attributed to the phenomenon of molecule capture within formed Ppy matrix. EQCM-resonators modified by MIP-Ppy showed the following advantages: selectivity, qualitative response, cost-effectiveness, and simple procedure. The selectivity of MIP-Ppy was tested by the replacement of uric acid in the PBS solution with several different concentrations of caffeine and glucose. Langmuir isotherm based molecular adsorption model was applied to evaluate the interaction of MIP-Ppy with uric acid. From experimental results calculated the standard Gibbs free energy of association (ΔG) of uric acid with MIP-Ppy is -16.4 ± 2.05 kJ/mol and with NIP-Ppy is -13.3 ± 8.56 kJ/mol ΔG values illustrate that the formation of uric acid complex with MIP-Ppy is thermodynamically more favourable than that for complexation with NIP-Ppy.
尿酸印迹聚吡咯基（MIP-Ppy）电化学石英晶体微天平传感器（EQCM）已被开发。实验和理论计算集中在尿酸分子与：i）尿酸印迹的聚吡咯（MIP-Ppy）ii）无任何分子印迹的聚吡咯膜之间的分子相互作用。在 MIP-Ppy 和 NIP-Ppy 薄膜的电化学沉积过程中观察到共振频率差异，这归因于在形成的 Ppy 基质内捕获分子的现象。通过 MIP-Ppy 修饰的 EQCM 谐振器具有以下优点：选择性、定性响应、经济高效和简单的程序。通过用几种不同浓度的咖啡因和葡萄糖替代 PBS 溶液中的尿酸来测试 MIP-Ppy 的选择性。应用基于 Langmuir 等温线的分子吸附模型来评估 MIP-Ppy 与尿酸的相互作用。从实验结果中计算出尿酸与 MIP-Ppy 的结合标准吉布斯自由能（ΔG）为-16.4±2.05 kJ/mol，与 NIP-Ppy 的结合标准吉布斯自由能为-13.3±8.56 kJ/mol。ΔG 值表明尿酸与 MIP-Ppy 形成复合物在热力学上比与 NIP-Ppy 形成复合物更有利。
