基于石墨烯和壳聚糖复合膜构建的电化学传感器检测尿酸研究

Study on Detection of Uric Acid by Electrochemical Sensor Based on Graphene and Chitosan Composite Membrane

目的构建基于石墨烯(GR)和壳聚糖(CHI)复合膜的电化学传感器对尿酸进行检测和研究。方法通过扫描电子显微镜对石墨烯进行形貌分析;采用循环伏安法、差分脉冲伏安法和交流阻抗法等来研究尿酸在石墨烯/壳聚糖修饰的玻碳电极上的电化学行为,并评估其检测性能。采集2017年9月24日三名实验人员的晨尿,用构建的传感器来对生物样本进行检测。结果扫描电子显微镜下石墨烯呈片层结构。GR/CHI复合膜构建的电化学传感器测定6～600μmol/L尿酸时具有良好的线性关系(R^2=0.993 4),检测限为0.33μmol/L(S/N=3);同时讨论了扫描速度、修饰量、pH及干扰物对尿酸测定的电化学行为的影响。尿酸的加标回收率在97.5%～101.3%之间。结论该传感器生产简单,特异度好,稳定性高,可用于实际尿酸样品的检测,为临床尿酸测定提供了新的应用前景。

Objective An electrochemical sensor based on graphene （GR） and chitosan （CHI） composite membranes was constructed to detect and study uric acid. Methods The morphology of graphene was analysed by scanning electron microscopy, cyclic voltammetry, differential pulse voltammetry and electrochemical impedance spectroscopy method were used for detecting the electrochemical behavior of uric acid at glassy carbon electrode modified by graphene/chitosan; and the detection performance was evaluate. Collected three experimenters morning urine on September 24,2017. The proposed sensor was used for biological samples detection. Results The results showed that the graphene appeared as a layer structure under scanning electron microscope. The concentration in the 6-600 ttmol/L range showed a good linear relationship and the detection limit was 0.33 μmol/L （S/N=3）. The effects of sweep rate, modification amount, pH and interference on electrochemical behavior of UA were also discussed. The standard addition recovery rate of UA was in 97.5 % -101.3% . Conclusion The sensor has advantages of simple production,good specificity and high stability. It can be used for the detection of uricacid samples,and provides a new application prospect for clinical uric acid detection.