Abstract In this study, the Co3O4.Fe2O3 nanospheres (NSs) was prepared by hydrothermal process in high alkaline environment of pH 10.5. X-ray photoelectron spectroscopy (XPS), field Emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction analysis were performed to characterize the prepared Co3O4.Fe2O3 NSs. The Co3O4.Fe2O3 NSs was subjected to deposit onto a glassy carbon electrode (GCE) of 0.0316 cm2 surface area with nafion (5% suspension in ethanol) adhesive as thin film to obtain the desire ascorbic acid (AA) sensor. The calibration curve of AA sensor was plotted as current versus concentration of AA, which is a linear from 0.1 nM to 0.01 mM on calibration curve defined as linear dynamic range (LDR). The slope of LDR is used to calculate the sensitivity of sensor by considering the active surface area of electrode and is equal to 15.4367 µAµM−1cm−2. The limit of detection (LOD; 96.02 ± 4.80 pM) and the limit of quantification (LOQ; 320.07 ± 10.0 pM) of AA sensor are calculated. The reproducibility, response time and long-time stability of sensor are exhibited as outstanding. The electrochemical analyzing of real samples, the AA sensor is shown its reliability.

中文翻译：

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Co3O4.Fe2O3纳米球材料电化学制备抗坏血酸传感器

摘要 本研究在pH 10.5 的高碱性环境中通过水热法制备了Co3O4.Fe2O3 纳米球(NSs)。进行 X 射线光电子能谱 (XPS)、场发射扫描电子显微镜 (FESEM)、能量色散 X 射线光谱 (EDS) 和 X 射线衍射分析来表征制备的 Co3O4.Fe2O3 NSs。将 Co3O4.Fe2O3 NSs 沉积到表面积为 0.0316 cm2 的玻璃碳电极 (GCE) 上，使用 nafion（乙醇中的 5% 悬浮液）粘合剂作为薄膜，以获得所需的抗坏血酸 (AA) 传感器。AA 传感器的校准曲线绘制为电流与 AA 浓度的关系，在校准曲线上线性从 0.1 nM 到 0.01 mM，定义为线性动态范围 (LDR)。LDR 的斜率用于通过考虑电极的活性表面积来计算传感器的灵敏度，等于 15.4367 µAµM-1cm-2。计算 AA 传感器的检测限 (LOD; 96.02 ± 4.80 pM) 和定量限 (LOQ; 320.07 ± 10.0 pM)。传感器的再现性、响应时间和长期稳定性表现出色。实际样品的电化学分析表明，AA 传感器具有可靠性。