Department of Medical Physics and Biomedical Engineering, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
Chemistry & Chemical Engineering Research Center of Iran, Tehran, 14335-186, Iran.
Sci Rep. 2019 Aug 13;9(1):11775. doi: 10.1038/s41598-019-47420-0.
We report on a combined experimental and theoretical study concerning the electrochemical behavior of the dexamethasone (DEX) on a graphene modified glassy carbon electrode (GCE). A good agreement between experiments and density functional theory (DFT)-based calculations is observed for the DEX reduction. The electrochemical behavior of the DEX was investigated on the surface of a glassy carbon electrode (GCE) modified with different type of graphenes, including graphene quantum dot (GQD), graphene oxide (GO), electrochemically synthesized graphene (EG), graphene synthesized by the Hummer method (HG) and graphene nanoplate (GNP) using voltammetric techniques (CV, DPV and SWV). The results exhibited a significant increase in the reduction of the peak current of the DEX in the GNP modified GCE (GNP/GCE) in comparison to other modified electrodes and bare GCE. The unique morphology, size and electro catalytic properties of the GNP cause a sensitive response of the DEX in a novel sensor. Under the optimized experimental condition, the GNP/ GCE showed two linear dynamic ranges of 0.1-50 μM and 50-5000 μM with a low detection limit of 15 nM for determination of the DEX. The novel sensor is successfully applied to the sensitive determination of the DEX in human plasma samples with satisfactory recoveries. Energy of the LUMO and HUMO orbitals and energy calculations for the DEX molecule interacting with graphene were performed using the density functional B3LYP/6-31G. The theoretical results allied to significant charge transfer took place due to the interaction of the DEX with the applied graphene.
我们报告了一项关于地塞米松（DEX）在修饰玻碳电极（GCE）上的电化学行为的实验和理论研究。DEX 的还原实验和基于密度泛函理论（DFT）的计算结果非常吻合。我们在不同类型的石墨烯修饰玻碳电极（GCE）表面上研究了 DEX 的电化学行为，包括石墨烯量子点（GQD）、氧化石墨烯（GO）、电化学合成的石墨烯（EG）、Hummer 法合成的石墨烯（HG）和石墨烯纳米片（GNP），使用了伏安技术（CV、DPV 和 SWV）。结果表明，与其他修饰电极和裸 GCE 相比，在 GNP 修饰的 GCE（GNP/GCE）上，DEX 的还原峰电流显著增加。GNP 的独特形态、尺寸和电催化性能导致了 DEX 在新型传感器中的敏感响应。在优化的实验条件下，GNP/ GCE 对 DEX 的检测呈现出两个线性动态范围，分别为 0.1-50 μM 和 50-5000 μM，检测限低至 15 nM。该新型传感器成功应用于人血浆样品中 DEX 的灵敏测定，回收率令人满意。使用密度泛函 B3LYP/6-31G 对 LUMO 和 HUMO 轨道能量以及 DEX 分子与石墨烯相互作用的能量计算进行了计算。理论结果表明，由于 DEX 与施加的石墨烯相互作用，发生了显著的电荷转移。
