Abstract In this study, we have synthesized MgNi2O3 and Fe-doped MgNi2O3 by sol-gel method and characterized the products by powder X-ray diffraction, UV–visible spectroscopy, vibrating sample magnetometer, X-ray photoelectron spectroscopy, scanning and transmission electron microscopy for confirmation of morphology, optical, structural, and magnetic properties. An electrochemical sensor based on 2.5 wt% Fe doped MgNi2O3 nanoparticles modified glassy carbon electrode (GCE) has been fabricated and used for simultaneous electrochemical sensing of Dopamine (DA), Uric Acid (UA), Nicotine (NIC), and Caffeine (CA) for the first time. The MgNi1.95Fe0.05O3 modified GCE shows four strong well-defined separate oxidation peaks of DA, UA, NIC and CA in their mixture in both cyclic and square wave voltammetry studies in phosphate buffer saline (pH 7). Under optimized experimental conditions, oxidation currents increased linearly with the increase in concentration over very wide ranges of 0.1–1000, 0.1–5000, 50–6000, and 50–4000 μM for DA, UA, NIC and CA and the corresponding lowest detection limits (LODs) were calculated as 0.017, 0.104, 0.098 and 0.276 μM (S/N = 3) respectively. These measurable concentration ranges and LODs are much higher than the values ever reported in the literature for the sensor made of a simple stable electrode material Fe-MgNi2O3 without requiring adhesives, enzymes or modifiers.

中文翻译：

---

基于 Fe 掺杂的 MgNi2O3 纳米颗粒的新型电化学传感器，用于在非常宽的线性范围内同时测定多巴胺、尿酸、尼古丁和咖啡因

摘要 在本研究中，我们采用溶胶-凝胶法合成了 MgNi2O3 和 Fe 掺杂的 MgNi2O3，并通过粉末 X 射线衍射、紫外-可见光谱、振动样品磁强计、X 射线光电子能谱、扫描和透射电子显微镜对产物进行了表征。用于确认形态、光学、结构和磁性特性。基于 2.5 wt% Fe 掺杂的 MgNi2O3 纳米颗粒修饰的玻碳电极 (GCE) 的电化学传感器已被制造并用于同时电化学传感多巴胺 (DA)、尿酸 (UA)、尼古丁 (NIC) 和咖啡因 (CA)首次。MgNi1.95Fe0.05O3 修饰的 GCE 在磷酸盐缓冲盐水 (pH 7) 中的循环和方波伏安法研究中显示出 DA、UA、NIC 和 CA 在其混合物中的四个强明确的独立氧化峰。在优化的实验条件下，DA、UA、NIC 和 CA 的氧化电流在 0.1-1000、0.1-5000、50-6000 和 50-4000 μM 的很宽范围内随着浓度的增加而线性增加，以及相应的最低检测限(LOD) 分别计算为 0.017、0.104、0.098 和 0.276 μM (S/N = 3)。这些可测量的浓度范围和 LOD 远高于文献中报道的由简单稳定的电极材料 Fe-MgNi2O3 制成的传感器的值，无需粘合剂、酶或改性剂。分别为 098 和 0.276 μM (S/N = 3)。这些可测量的浓度范围和 LOD 远高于文献中报道的由简单稳定的电极材料 Fe-MgNi2O3 制成的传感器的值，无需粘合剂、酶或改性剂。分别为 098 和 0.276 μM (S/N = 3)。这些可测量的浓度范围和 LOD 远高于文献中报道的由简单稳定的电极材料 Fe-MgNi2O3 制成的传感器的值，无需粘合剂、酶或改性剂。