Electrochemistry and Chemistry of Materials, Department of Chemistry, University of Dschang, Dschang P.O. Box 67, Cameroon.
Institut für Anorganische Chemie und Strukturchemie, Heinrich-Heine-Universität Düsseldorf, 40204 Düsseldorf, Germany.
Sensors (Basel). 2022 Aug 18;22(16):6173. doi: 10.3390/s22166173.
In this work, an electrode modified with an amino-functionalized clay mineral was used for the electrochemical analysis and quantification of quercetin (QCT). The resulting amine laponite (LaNH) was used as modifier for a glassy carbon electrode (GCE). The organic-inorganic hybrid material was structurally characterized using X-ray diffraction, Fourier transformed infrared spectroscopy (FTIR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and CHN elemental analysis. The covalent grafting of the organosilane to the clay backbone was confirmed. The charge on the aminated laponite, both without and with the protonation of NH groups, was evaluated via cyclic voltammetry. On the protonated amine (LaNH)-modified GCE, the cyclic voltammograms for QCT showed two oxidation peaks and one reduction peak in the range of -0.2 V to 1.2 V in a phosphate buffer-ethanol mixture at pH 3. By using the differential pulse voltammetry (DPV), the modification showed an increase in the electrode performance and a strong pH dependence. The experimental conditions were optimized, with the results showing that the peak current intensity of the DPV increased linearly with the QCT concentration in the range from 2 × 10 M to 2 × 10 M, leading to a detection limit of 2.63 × 10 M (S/N 3). The sensor selectivity was also evaluated in the presence of interfering species. Finally, the proposed aminated organoclay-modified electrode was successfully applied for the detection of QCT in human urine. The accuracy of the results achieved with the sensor was evaluated by comparing the results obtained using UV-visible spectrometry.
在这项工作中，使用经过氨基功能化粘土矿物修饰的电极进行电化学分析和槲皮素（QCT）定量。所得的胺蒙脱土（LaNH）用作玻璃碳电极（GCE）的修饰剂。使用 X 射线衍射、傅里叶变换红外光谱（FTIR）、扫描电子显微镜（SEM）、热重分析（TGA）和 CHN 元素分析对有机-无机杂化材料进行结构表征。证实了有机硅烷到粘土骨架的共价接枝。通过循环伏安法评估了未质子化和 NH 基团质子化的胺化蒙脱土的电荷。在质子化的胺（LaNH）修饰的 GCE 上，QCT 的循环伏安图在 pH 3 的磷酸盐缓冲-乙醇混合物中在-0.2 V 至 1.2 V 的范围内显示出两个氧化峰和一个还原峰。通过使用差分脉冲伏安法（DPV），修饰显示出电极性能的提高和强烈的 pH 依赖性。优化了实验条件，结果表明 DPV 的峰电流强度与 2×10-5 M 至 2×10-4 M 范围内的 QCT 浓度呈线性增加，导致检测限为 2.63×10-5 M（S/N 3）。还评估了存在干扰物质时传感器的选择性。最后，成功地将提出的胺化有机粘土修饰电极应用于人尿中 QCT 的检测。通过将传感器获得的结果与紫外可见光谱法获得的结果进行比较，评估了传感器结果的准确性。
