Abstract Porous alumina microfibers with a diameter of 125 nm were prepared through hydrothermal reaction in urea solution using aluminium nitrate as the precursor, and characterized using transmission electron microscopy and scanning electron microscopy. The mechanism of oxidation of chlorogenic acid was examined using cyclic voltammetry, indicating a reversible two-electron process. Compared with the bare carbon paste electrode (CPE), the oxidation signals of chlorogenic acid were greatly enhanced with the alumina microfiber-modified CPE. Chronocoulometry experiments indicated that the accumulation of chlorogenic acid on the surface of the alumina microfibers was obviously improved relative to that on the bare electrode, which is attributed to the numerous micropores and regular fiber-like structures. Based on the signal amplification ability of the porous alumina microfibers, a novel electrochemical sensing platform was developed for chlorogenic acid. The linear range was 10–2000 μg L−1, and the limit of detection was evaluated to be 5.0 μg L−1. The practical application of this new method was demonstrated using honeysuckle and soft drink samples. The results were consistent with the values obtained by high-performance liquid chromatography.

中文翻译：

---

多孔氧化铝微纤维对绿原酸电化学传感的表面增强

摘要 以硝酸铝为前驱体，在尿素溶液中通过水热反应制备直径为125 nm的多孔氧化铝微纤维，并用透射电镜和扫描电镜对其进行表征。使用循环伏安法检查绿原酸的氧化机制，表明可逆的双电子过程。与裸碳糊电极（CPE）相比，氧化铝微纤维改性的 CPE 大大增强了绿原酸的氧化信号。计时库仑法实验表明，与裸电极相比，氧化铝微纤维表面绿原酸的积累明显改善，这归因于大量微孔和规则的纤维状结构。基于多孔氧化铝微纤维的信号放大能力，开发了一种新型的绿原酸电化学传感平台。线性范围为 10–2000 μg L-1，检测限估计为 5.0 μg L-1。使用金银花和软饮料样品证明了这种新方法的实际应用。结果与高效液相色谱法得到的值一致。