Department of Analytical Chemistry, Kazan Federal University, Kremleyevskaya, 18, 420008 Kazan, Russia.
Department of High Molecular and Organoelement Compounds, Kazan Federal University, Kremleyevskaya, 18, 420008 Kazan, Russia.
Sensors (Basel). 2021 Dec 31;22(1):288. doi: 10.3390/s22010288.
Natural phenolic antioxidants are one of the widely studied compounds in life sciences due to their important role in oxidative stress prevention and repair. The structural similarity of these antioxidants and their simultaneous presence in the plant samples stipulate the development of methods for their quantification. The current work deals with the simultaneous determination of vanillin and its bioprecursor ferulic acid using a voltammetric sensor for the first time. A sensor based on the layer-by-layer deposition of the polyaminobenzene sulfonic acid functionalized single-walled carbon nanotubes (f-SWCNTs) and electropolymerized bromocresol purple has been developed for this purpose. The best response of co-existing target analytes was registered for the polymer obtained from the 25 µM dye by 10-fold potential cycling from 0.0 to 1.2 V with the scan rate of 100 mV s in 0.1 M phosphate buffer (PB), pH 7.0. Scanning electron microscopy (SEM), cyclic voltammetry and electrochemical impedance spectroscopy (EIS) confirmed the effectivity of the sensor developed. The linear dynamic ranges of 0.10-5.0 µM and 5.0-25 µM for both analytes with the detection limits of 72 nM and 64 nM for ferulic acid and vanillin, respectively, were achieved in differential pulse mode. The sensor was applied for the analysis of vanilla extracts.
天然酚类抗氧化剂因其在氧化应激预防和修复中的重要作用，是生命科学中研究广泛的化合物之一。这些抗氧化剂的结构相似性及其在植物样品中的同时存在，规定了其定量方法的发展。目前的工作首次涉及使用伏安传感器同时测定香草醛及其生物前体阿魏酸。为此，开发了一种基于聚氨基苯磺酸功能化单壁碳纳米管（f-SWCNTs）的层层沉积和电聚合溴甲酚紫的传感器。对于从 25µM 染料获得的聚合物，通过在 0.1M 磷酸盐缓冲液（PB），pH 7.0 中以 100mV/s 的扫描速率从 0.0 到 1.2V 进行 10 倍电位循环，记录到共存目标分析物的最佳响应。扫描电子显微镜（SEM）、循环伏安法和电化学阻抗谱（EIS）证实了所开发传感器的有效性。在差分脉冲模式下，两种分析物的线性动态范围分别为 0.10-5.0µM 和 5.0-25µM，检测限分别为阿魏酸和香草醛的 72nM 和 64nM。该传感器已应用于香草提取物的分析。
