Jakkrawhad Chanida, Makkliang Fonthip, Nurerk Piyaluk, Siaj Mohamed, Poorahong Sujittra
Functional Materials and Nanotechnology Center of Excellence, Walailak University Thasala Nakhon Si Thammarat 80160 Thailand
Department of Chemistry, School of Science, Walailak University Thasala Nakhon Si Thammarat 80160 Thailand.
RSC Adv. 2024 Jul 31;14(33):23921-23929. doi: 10.1039/d4ra03815k. eCollection 2024 Jul 26.
A highly stable flow-injection amperometric sensor for dexamethasone (DEX) was developed using a pencil graphite electrode (PGE) modified with Fe-based metal organic frameworks, MIL-100(Fe) and graphene oxide composite materials (MIL-100(Fe)/GO). Scanning electron microscopy and energy-dispersive X-ray spectroscopy, transmission electron microscopy, powder X-ray diffraction, and Fourier-transform infrared spectroscopy were used to characterize the MIL-100(Fe) composites. The MIL-100(Fe)/GO-modified PGE (denoted MIL-100(Fe)/GO/PGE) was further electrochemically characterized using cyclic voltammetry. As an electrode material, MIL-100(Fe) is a sensing element that undergoes oxidation from Fe(ii)-MOF to Fe(iii)-MOF, and GO possesses high conductivity and a large surface area, which exhibits high absorbability. In the presence of DEX, Fe(iii) is reduced, which accelerates electron transfer at the electrode interface. Therefore, DEX can be quantitatively detected by analyzing the anodic current of MIL-100(Fe). When coupled with amperometric flow injection analysis, excellent performance can be obtained even when a low detection potential is applied (+0.10 V Ag/AgCl). The concentration was linear in the range 0.10-5.0 μM and 0.010-5.0 mM with LOD of 0.030 μM based on 3(sd/slope). The modified electrode also exhibited a remarkably stable response under optimized conditions, and up to 55 injections can be used per electrode. The sensor exhibits high repeatability, reproducibility, and anti-interference properties when used for DEX detection. The effective determination of dexamethasone in real pharmaceutical and cosmetic samples demonstrated the feasibility of the electrochemical sensor, and the results were in good agreement with those obtained from the HPLC-DAD analysis. Acceptable percentage recoveries from the spiked pharmaceutical and cosmetic samples were obtained, ranging from 93-111% for this new method compared with 84-107% for the HPLC-DAD standard method.
采用铁基金属有机框架材料MIL-100(Fe)与氧化石墨烯复合材料(MIL-100(Fe)/GO)修饰的铅笔石墨电极(PGE)，研制了一种用于地塞米松(DEX)的高稳定性流动注射安培传感器。利用扫描电子显微镜、能量色散X射线光谱、透射电子显微镜、粉末X射线衍射和傅里叶变换红外光谱对MIL-100(Fe)复合材料进行了表征。采用循环伏安法对MIL-100(Fe)/GO修饰的PGE(记为MIL-100(Fe)/GO/PGE)进行了电化学表征。作为电极材料，MIL-100(Fe)是一种传感元件，它从Fe(ii)-MOF氧化为Fe(iii)-MOF，而GO具有高导电性和大表面积，表现出高吸附性。在DEX存在下，Fe(iii)被还原，加速了电极界面的电子转移。因此，通过分析MIL-100(Fe)的阳极电流可以定量检测DEX。与安培流动注射分析相结合时，即使施加低检测电位(+0.10 V Ag/AgCl)也能获得优异的性能。浓度在0.10-5.0 μM和0.010-5.0 mM范围内呈线性，基于3(sd/slope)的检测限为0.030 μM。修饰电极在优化条件下也表现出非常稳定的响应，每个电极最多可进行55次进样。该传感器用于DEX检测时具有高重复性、重现性和抗干扰性能。实际药物和化妆品样品中地塞米松的有效测定证明了该电化学传感器的可行性，结果与HPLC-DAD分析结果吻合良好。加标药物和化妆品样品的回收率在93%-111%之间，该新方法与HPLC-DAD标准方法的回收率在84%-107%之间。
