A voltammetric sensor based on the electropolymerization of cobalt-poly(methionine) (Co-poly(Met)) on a glassy carbon electrode (GCE) was developed and applied for the determination of estriol by differential pulse voltammetry (DPV) for the first time. The electrochemical properties of the Co-poly(Met)/GCE were analysed by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to characterize the polymers on the GCE surface. The deposition of the Co-poly(Met) film on the GCE surface enhanced the sensor electronic transfer. CV studies revealed that estriol exhibits an irreversible oxidation peak at +0.58 V for the Co-poly(Met)/GCE (vs. Ag/AgCl reference electrode) in 0.10 mol/L Britton-Robinson buffer solution (pH = 7.0). Different voltammetric scan rates (10–200 mV/s) suggested that the estriol oxidation on the Co-poly(Met)/GCE surface is controlled by adsorption and diffusion processes. Based on the optimized DPV conditions, the linear responses for estriol quantification were from 0.596 μmol/L to 4.76 μmol/L (R² = 0.996) and from 5.66 μmol/L to 9.90 μmol/L (R² = 0.994) with a limit of detection (LOD) of 0.0340 μmol/L and a limit of quantification (LOQ) of 0.113 μmol/L. The DPV-Co-poly(Met)/GCE method provided good intra-day and inter-day repeatability with RSD values lower than 5%. Also, no interference of real sample matrices was observed on the estriol voltammetric response, making the DPV-Co-poly(Met)/GCE highly selective for estriol. The accuracy test showed that the estriol recovery was in the ranges 96.7%–103% and 98.7%–102% for pharmaceutical tablets and human urine, respectively. The estriol quantification in pharmaceutical tablets performed by the Co-poly(Met)/GCE-assisted DPV method was comparable to the official analytical protocols.

开发了基于钴-聚（蛋氨酸）（Co-poly（Met））在玻璃碳电极（GCE）上进行电聚合的伏安传感器，并将其首次用于微分脉冲伏安法（DPV）测定雌三醇。 。通过循环伏安法（CV）和电化学阻抗谱（EIS）分析了Co-poly（Met）/ GCE的电化学性质。扫描电子显微镜（SEM）和能量色散光谱（EDS）用于表征GCE表面上的聚合物。Co-poly（Met）膜在GCE表面上的沉积增强了传感器的电子传输。CV研究表明，在0.10 mol / L的Britton-Robinson缓冲溶液（pH = 7.0）中，对于多聚（Met）/ GCE（相对于Ag / AgCl参比电极），雌三醇在+0.58 V处显示出不可逆的氧化峰。不同的伏安扫描速率（10–200 mV / s）表明，Co-poly（Met）/ GCE表面上的雌三醇氧化是由吸附和扩散过程控制的。根据优化的DPV条件，雌三醇定量的线性响应为0.596μmol/ L至4.76μmol/ L（R²  = 0.996）和 5.66μmol/ L至9.90μmol / L（R ² = 0.994），检测限（LOD）为0.0340μmol/ L，定量限（LOQ）为0.113μmol/ L。DPV-Co-poly（Met）/ GCE方法提供良好的日内和日间重复性，RSD值低于5％。此外，在雌三醇的伏安响应中未观察到实际样品基质的干扰，这使得DPV-Co-poly（Met）/ GCE对雌三醇具有高度选择性。准确性测试表明，对于药用片剂和人尿，雌三醇的回收率分别为96.7％–103％和98.7％–102％。通过Co-poly（Met）/ GCE辅助DPV方法进行的药用片剂中的雌三醇定量可与官方分析方案相媲美。