L-苏氨酸分子印迹传感器的制备及应用

Preparation of a Molecularly Imprinted Film Modified Electrochemical Sensor for L-threonine Determination

采用电化学方法制备了纳米银/聚槲皮素修饰充蜡石墨电极(Ag/Qu/WGE)。以L-苏氨酸(L-Thr)为模板分子,将一定量的壳聚糖,L-Thr和Nafion的混合液涂布在Ag/Qu/WGE上,采用恒电位法电化学清洗除去模板分子L-Thr,得到基于壳聚糖/纳米银/聚槲皮素的L-Thr分子印迹复合膜修饰电极(TMIP/WGE)。采用场发射扫描电镜、红外光谱分析、X射线光电子能谱和电化学技术表征了TMIP/WGE的形成。TMIP/WGE对L-Thr具有良好的电催化氧化作用,可用于L-Thr的快速、灵敏检测,L-Thr的氧化峰电流(1.45 V)和其浓度在0.1~1.0μmol/L范围内呈良好的线性关系,检出限(3σ)为0.01μmol/L。该电极已成功用于苏氨酸发酵液中L-Thr的检测。

A nano-silver/poly quercetin composites modified paraffin-impregnated graphite electrode was prepared by electrochemical method（Ag/Qu/WGE）.A mixture of L-Thr,chitosan and Nafion was coated on the surface of Ag/Qu/WGE,L Thr（template molecule） was removed by electrochemical cleaning using potentiostatic method.As a result,a molecular imprinted polymer modified electrode based on chitosan/nano-silver/poly quercetin composites could be obtained for L-Thr detection（TMIP/WGE）.The characteristics of the modified electrode were investigated by means of field emission scanning electron microscope technique,X-ray photoelectron spectroscopy,infrared spectra and electrochemical technique.The result indicated that the TMIP/WGE displayed a good electro-catalysis towards the oxidation of L-Thr,which could be used for sensitive and quick detection of L-Thr.The differences of oxidation peak current of L-Thr（1.45 V） showed a good linearity in the concentration range of 0.1-1.0 μmol/L with a detection limit（3σ） of 0.01 μmol/L.The electrode was successfully applied in the determination of L-Thr in fermentation broth.