Preparation and characterizations of poly(pyrrole-co-pyrrole-3-carboxylic acid) (PPYPA) film on the surface of screen printed carbon electrode (SPE) has been discussed in the manuscript. Different ratios of monomer for PPYPA preparation will be applied to determine 17β-estradiol using cyclic voltammetry. The SPE was modified with PPYPA film using an electrodeposition method and followed by the immobilization of 75mer aptamer specifically binding to 17β-estradiol as a model study. The materials were characterized by cyclic voltammetry, Fourier transform infrared, electrochemical impedance spectroscopy and scanning electron microscopy. The redox peak potential was found to be at 0.13 V and 0.26 V. The appearance of cauliflower structure in the SEM image which indicates PPYPA film was formed on SPE. Moreover, PPYPA/SPE exhibited a lower charge transfer resistance (Rct) compared to bare SPE indicates a good conductivity of film. Our study shows that 3:1 ratio between PPY and pyrrole-3-carboxylic acid provided highly active surface area for the immobilization of 75mer aptamer for 17β-estradiol detection.

制备与聚表征（吡咯共手稿中已讨论了丝网印刷碳电极（SPE）表面的-吡咯-3-羧酸（PPYPA）膜。将使用不同比例的PPYPA制备单体，使用循环伏安法测定17β-雌二醇。作为模型研究，使用电沉积方法用PPYPA膜对SPE进行修饰，然后固定与17β-雌二醇特异性结合的75mer适体的固定化。通过循环伏安法，傅里叶变换红外光谱，电化学阻抗谱和扫描电子显微镜对材料进行了表征。发现氧化还原峰电位为0.13V和0.26V。在SEM图像中出现花椰菜结构，这表明在SPE上形成了PPYPA膜。而且，与裸露的SPE相比，PPYPA / SPE表现出较低的电荷转移电阻（Rct），表明薄膜具有良好的导电性。我们的研究表明，PPY与吡咯3-羧酸之比为3：1，可为固定75聚体适体以检测17β-雌二醇提供高活性的表面积。