基于适配体的石墨烯修饰玻碳电极检测卡那霉素

Aptamer-based Detection of Kanamycin Using Graphene Modified Glassy Carbon Electrode

建立了一种基于适配体和石墨烯修饰玻碳电极检测卡那霉素的方法。卡那霉素适配体（Kanaaptamer）可以吸附在石墨烯（Gr）修饰的电极表面,从而阻碍电化学探针[Fe（CN）6]3-/4-与电极表面的电子传递,然而与含有卡那霉素的样品反应后,卡那霉素能与适配体结合并使其从电极上置换脱落,对界面电子传递的阻碍作用降低,探针的电化学信号得到恢复。通过循环伏安法和原子力显微镜法对该过程进行了表征。该原理被用于对卡那霉素进行电化学检测,结果表明：在优化条件下,用差分脉冲伏安法（DPV）检测卡那霉素时,其线性范围为1×10-6~1×10-5mol/L,检出限为5×10-7mol/L。该方法应用于牛奶样品中卡那霉素的检测,结果满意。

A method of aptamer-based detection of kanamycin was established by using a graphene modified glassy carbon electrode. Kanamycin-specific aptamer（ Kana-aptamer） could be adsorbed onto the graphene（ Gr） modified electrode,which prevents the electron transfer between the probe[Fe（ CN）6]3-/4-and the electrode. However,after incubation with samples containing kanamycin,kanamycin could bind with aptamer and replace it from the electrode,which in turn declines the resistance of the electron transfer and recovers the electrochemical signal. The procedure was firstly characterized by cyclic voltametry（ CV） and atomic force microscopy. Then this replacement effect was utilized to electrochemically determine kanamycin. Under the optimized conditions,kanamycin could be determined by differential pulse voltammetry（ DPV）,and the calibration curve was linear in the range of 1 × 10-6-1 × 10-5mol / L,with a detection limit of 5 × 10-7mol / L. The method was successfully applied in the detection of kanamycin in milk samples with satisfactory result.