二氧化铈/多壁碳纳米管/乙炔黑纳米电化学传感器法快速测定苦荞总黄酮

Rapid determination of total flavonoids in Tartary buckwheat by cerium dioxide/multi-walled carbon nanotubes/acetylene black nano-electrochemical sensor method

中文关键词:  荞麦  总黄酮  纳米材料  电化学传感器

英文关键词:Tartary buckwheat  total flavonoids  nanometer material  electrochemical sensor

中文摘要:

      目的 建立基于二氧化铈/多壁碳纳米管/乙炔黑(cerium dioxide/multi-walled carbon nanotubes/acetylene black, CeO2/MWCNTs/AB)纳米电化学传感器法快速测定苦荞麦总黄酮的分析方法。方法 采用扫描电镜、循环伏安法、阻抗技术对修饰材料及其传感器进行表征, 通过循环伏安法探究芦丁在电极表面上的电化学行为, 并对电解液的选择、pH、修饰液的比例、滴涂量、富集时间以及扫描速度等条件进行优化, 进行苦荞麦黄酮的测定。结果 循环伏安图表明在0.54 V与0.57 V电位处出现对称的氧化峰和还原峰, 证实黄酮类化合物的电化学氧化还原反应具有可逆性。对实验条件进行了优化, 结果如下: pH为2.0的B-R溶液作为电解质溶液, CeO2/MWCNTs与乙炔黑的比例1:3 (V:V), 复合修饰材料修饰量12 μL, 富集时间9 min。苦荞麦黄酮氧化峰电流与其浓度之间呈良好的线性关系, 线性方程为Ip=0.793C+3.508 (r2=0.998), 最低检出限可达到6.5×10–8 mol/L。该方法用于苦荞麦中总黄酮的检测, 其加标回收率为99.46%~102.15%。结论 该方法的检测结果优于紫外-可见光分光光度法, 同时具有样品预处理简单、快捷方便、检测成本低、灵敏度高、准确性好等优势, 可用于食品中总黄酮快速准确的分析。

英文摘要:

      Objective To establish a method for the rapid determination of total flavonoids in tartary buckwheat by cerium dioxide/multi-walled carbon nanotubes/acetylene black (CeO2/MWCNTs/AB) nano-electrochemical sensor. Methods The modified material and these nanoelectrochemical sensors were characterized by scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The electrochemical behavior of rutin on the electrode surface was systematically investigated via CV. Critical parameters were optimized, including electrolyte type, pH, modifier ratio, coating volume, accumulation time and scan rate. Results One pair of well- defined redox peaks were observed at the potential of 0.54 V and 0.57 V, which indicated that the electrochemical oxidation and reduction reaction of flavonoid was reversible. The experimental conditions were optimized, the results as follows: B-R solution with pH 2.0 as the electrolyte solution, VCeO2/MWCNTs:Vacetylene black as 1:3, amounts of modified material, 12 μL, enrichment time as 9 min. At these conditions, the oxidation peak current of flavonoid linearly increased with its concentration, Ip=0.793C+3.508 (r2=0.998), and the limit of detection was 6.5×10–8 mol/L. The developed method was used to determinate total flavonoids content of tartary buckwheat, the recoveries were in the range of 99.46%–102.15%, the results were superior to ultraviolet-visible spectrophotometry. Conclusion The method is feasible for the rapid and accurate determination of total flavonoids in food with the advantages such as simple pretreatment time saving and convenience, low detection cost, high sensitivity and good accuracy.