金纳米材料制备及用于抗坏血酸电化学检测

Preparation of Gold Nanomaterials for Electrochemical Detection of Ascorbic Acid

摘要: 抗坏血酸(AA)是维持生命健康所必需的营养物质之一，所以对其进行测定具有重要意义。本文利用金纳米材料修饰玻碳电极实现对AA的检测。利用不同的塑型剂，通过直接还原法分别制备得到三种金纳米材料(金纳米锥、金纳米块、金纳米带)。用紫外–可见光谱(UV-Vis)和场发射电子扫描显微镜(SEM)对金纳米材料进行表征。采用直接滴涂法制备金纳米锥修饰电极、金纳米块修饰电极、金纳米带修饰电极，用循环伏安法(CV)和差分脉冲伏安法(DPV)，研究抗坏血酸(AA)在不同金纳米材料修饰电极上的电化学行为。结果表明，在含有一定量AA的pH 7.0的磷酸盐缓冲溶液(PBS)中，三种金纳米材料修饰电极对抗坏血酸都有良好的电流响应能力。并考察三种金纳米材料修饰电极检测AA的线性关系、干扰性、稳定性、加标回收、实际样品检测等。最低检出限可达5.38 μmol·L−1，加标回收的平均回收率为97.10%~101.45%。

Abstract: Ascorbic acid (AA) is one of the nutrients necessary for life and health, so it is important to measure its content. In this paper, the glassy carbon electrode modified by gold nanomaterials was used to detect AA. Three gold nanomaterials (gold nano-cones, gold nano-blocks, gold nano-belts) were prepared by direct reduction method using different excipients. The morphology, size and absorption spectra of gold nanomaterials were analyzed by UV-Vis and SEM. Gold nano-cone modified electrode, gold nano-block modified electrode and gold nano-belt modified electrode were prepared by direct drop coating method. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to study ascorbic acid (AA). The results showed the three gold nanomaterial modified electrodes had good electrocatalytic ability to ascorbic acid in phosphate buffer solution (PBS) containing a certain amount of ascorbic acid at pH 7.0, indicated that three modified electrodes can be used to detect ascorbic acid with 5.38 μmol·L−1 limit detection, and the average recovery was in the range of 97.10%~101.45%.