羧基化纳米多孔碳电化学适配体传感器的构建及其在维生素C检测中的应用

Construction of carboxylated nanoporous carbon powder electrochemical aptasensor and its application in vitamin C detection

中文关键词:  羧基化纳米多孔碳粉末  维生素C  适配体  丝网印刷电极  电化学传感器

英文关键词:carboxylated nanoporous carbon powder  vitamin C  aptamer  screen printed electrode  electrochemical sensor

中文摘要:

      目的 建立一种简单、灵敏度高、选择性好的电化学适配体传感器用于维生素C (vitamin C, VC)的快速检测。方法 将羧基化纳米多孔碳材料(carboxylated nanoporous carbon powder, NCP-COOH)修饰在丝网印刷电极(screen printed electrode, SPCE)表面, 为结合氨基修饰的适配体提供大量的活性位点, 构建新型适配体传感器。当VC存在时, 传感器表面的适配体与VC特异性结合导致差分脉冲伏安(differential pulse voltammetry, DPV)响应信号下降, 根据信号的变化实现对VC的定量检测。采用循环伏安法和交流阻抗法对传感器的构建过程及电化学性能进行考察, 并通过对NCP-COOH材料浓度、适配体浓度、缓冲液pH、孵育时间等条件的优化, 确定传感器对VC的最佳检测条件。结果 NCP-COOH具有大的比表面积, 良好的导电性和生物相容性, 能显著提高传感器的电化学性能。在最佳的实验条件下, 传感器在0.1~1000.0 μg/L范围内对VC有良好的响应, 检出限为0.01 μg/L, 用于实际样品的测定时回收率为92.5%~100.5%, 测定结果与GB 5009.86—2016《食品安全国家标准 食品中抗坏血酸的测定》相符。结论 该方法方便快捷、灵敏度高、选择性好, 能够应用于蔬菜样品中VC的准确测定, 为农产品中VC的快速检测提供了一种新方法。

英文摘要:

      Objective To establish a simple, high sensitivity and good selectivity electrochemical aptasensor for rapid detection of vitamin C (VC). Methods The carboxylated nanoporous carbon powder material (NCP-COOH) was modified on the surface of the screen printed electrode (SPCE) to provide a large number of active sites for binding the amine-modified aptamer, and a novel aptasensor was constructed. In the presence of VC, the aptamer on the sensor surface specifically binding with VC, resulted a decrease in the differential pulse voltammetry (DPV) response signal and the quantitative detection of VC was realized according to the change of signal. The cyclic voltammetry and electrochemical impedance spectroscopy were used to investigate the construction process and electrochemical performance of the sensor. The optimal detection conditions of VC were determined by optimizing NCP-COOH material concentration, aptamer concentration, buffer pH, incubation time. Results NCP-COOH had large specific surface area, good conductivity and biocompatibility, which could be significantly improved the electrochemical performance of the sensor. Under the optimal experimental conditions, the sensor had a good response to VC in the range of 0.1–1000.0 μg/L, and the limit of detection was 0.01 μg/L. The recovery rates were 92.5%–100.5% when used for the determination of actual samples and the measurement results were consistent with the GB 5009.86—2016 National standards for food safety-Determination of ascorbic acid in food. Conclusion The method is convenient, rapid, sensitive and selective, which can be applied to the accurate determination of VC in vegetable samples, and provides a new method for the rapid detection of VC in agricultural products.