Department of Physics, King Mongkut's University of Technology Thonburi (KMUTT), Bangkok 10140, Thailand.
Center of Excellence in Theoretical and Computational Science (TaCS-CoE), Faculty of Science, King Mongkut's University of Technology Thonburi (KMUTT), 126 Pracha Uthit Rd., Bang Mod, Thung Khru, Bangkok 10140, Thailand.
Molecules. 2021 May 13;26(10):2876. doi: 10.3390/molecules26102876.
The selectivity in the simultaneous detection of ascorbic acid (AA), dopamine (DA), and uric acid (UA) has been an open problem in the biosensing field. Many surface modification methods were carried out for glassy carbon electrodes (GCE), including the use of graphene oxide and amino acids as a selective layer. In this work, molecular dynamics (MD) simulations were performed to investigate the role of serine oligomers on the selectivity of the AA, DA, and UA analytes. Our models consisted of a graphene oxide (GO) sheet under a solvent environment. Serine tetramers were added into the simulation box and were adsorbed on the GO surface. Then, the adsorption of each analyte on the mixed surface was monitored from MD trajectories. It was found that the adsorption of AA was preferred by serine oligomers due to the largest number of hydrogen-bond forming functional groups of AA, causing a 10-fold increase of hydrogen bonds by the tetraserine adsorption layer. UA was the least preferred due to its highest aromaticity. Finally, the role of hydrogen bonds on the electron transfer selectivity of biosensors was discussed with some previous studies. AA radicals received electrons from serine through hydrogen bonds that promoted oxidation reaction and caused the negative shifts and separation of the oxidation potential in experiments, as DA and UA were less affected by serine. Agreement of the in vitro and in silico results could lead to other in silico designs of selective layers to detect other types of analyte molecules.
在生物传感领域，同时检测抗坏血酸（AA）、多巴胺（DA）和尿酸（UA）的选择性一直是一个悬而未决的问题。许多用于修饰玻碳电极（GCE）的表面的方法，包括使用氧化石墨烯和氨基酸作为选择性层。在这项工作中，通过分子动力学（MD）模拟研究了丝氨酸低聚物在 AA、DA 和 UA 分析物选择性中的作用。我们的模型由溶剂环境中的氧化石墨烯（GO）片组成。向模拟盒中添加丝氨酸四聚体，并将其吸附在 GO 表面上。然后，从 MD 轨迹监测每个分析物在混合表面上的吸附情况。结果发现，由于 AA 形成氢键的官能团数量最多，因此 AA 优先被丝氨酸低聚物吸附，导致四丝氨酸吸附层形成的氢键数量增加了 10 倍。UA 由于其芳香性最高，因此最不受欢迎。最后，讨论了氢键在生物传感器电子转移选择性中的作用，并与一些以前的研究进行了比较。AA 自由基通过氢键从丝氨酸中获得电子，这促进了氧化反应，导致实验中氧化电位的负移和分离，而 DA 和 UA 受丝氨酸的影响较小。体外和体内结果的一致性可以导致其他选择性层的体内设计来检测其他类型的分析物分子。
