【摘要】 该文以配体4-羧基苯基卟啉的锆基金属有机框架(Zr-MOF)作为载体材料,多巴胺为单体,在碱性条件下合成了聚多巴胺包覆的Zr-MOF复合材料(Zr-MOF-PDA)。采用红外光谱、热重分析、扫描电镜等方法对Zr-MOF-PDA进行表征。将Zr-MOF-PDA滴涂至玻碳电极(GCE)表面,构建了测定双酚A(BPA)的电化学传感器,并采用循环伏安法、计时库仑法和差分脉冲伏安法研究修饰电极的电化学行为。结果表明,Zr-MOF-PDA/GCE具有较好的导电性和较大的电极有效表面积,其对BPA的响应电流值分别为PDA/GCE、Zr-MOF/GCE、裸GCE的1.6、2.0和2.8倍。在优化条件下,Zr-MOF-PDA/GCE传感器对BPA的响应电流值与其浓度在0.01～1.4μmol/L范围内具有良好的线性关系,对BPA的检出限(S/N=3)为0.004μmol/L。该传感器对BPA具有较好的选择性,其用于河水、牛奶和塑料瓶中BPA的检测,加标回收率为98.4%～103%,相对标准偏差(RSD)为3.4%～4.4%。更多还原

【Abstract】 Bisphenol A(BPA)is an endocrine disrupting substance commonly used in the manufacture of plastics,which is harmful to human health.In this paper,an electrochemical sensor based on polydopamine-coated zirconium-based metalorganic framework(Zr-MOF-PDA)was constructed to detect BPA.Under the alkaline conditions,the Zr-MOF-PDA composite was synthesized with Zr-MOF(4-carboxyphenylporphyrin as the ligand)as the supporter material and dopamine as the monomer. The composite was characterized by infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy, and then modified onto the surface of glassy carbon electrode(GCE)for the determination of BPA.The electrochemical behaviors of the modified electrodes were investigated by cyclic voltammetry, chronocoulometry and differential pulse voltammetry. The cyclic voltammetry oxidation peak current values of Zr-MOF-PDA/GCE, Zr-MOF/GCE and bare GCE were 107. 3,93. 28 and 77. 51 μA,respectively,and their electrode effective surface areas were 0. 514,0. 667 and 0. 467 cm~2,respectively.The experimental results showed that the Zr-MOF-PDA/GCE had a good conductivity and a large effective surface area.The differential pulse voltammetry response current of the Zr-MOF-PDA/GCE for BPA were 1. 6,2. 0 and 2. 8 times of those of PDA/GCE,Zr-MOF/GCE and bare GCE,respectively.The Zr-MOF as a carrier material had an excellent conductivity and a large specific surface area.PDA contained a large amount of amine and catechol groups.Therefore,the Zr-MOF-PDA exhibited a high adsorption capability for BPA due to the hydrogen-bond interaction between Zr-MOF-PDA and BPA,which improved the detection sensitivity of the BPA electrochemical sensor.The electrochemical detection conditions were also studied,and the optimal conditions were as follows:concentration of Zr-MOF-PDA:3 mg/mL,adsorption time:6 min,and pH value of the phosphate buffer:9. 0.Under the optimal conditions,the Zr-MOF-PDA/GCE showed a good linear relationship for the detection of BPA in the range of 0. 01-1. 4 μmol/L,and the linear regression equation was I(μA)= 0. 283 9 C(μmol/L)+0. 02(r~2= 0. 993 6).The detection limit(S/N = 3)for BPA was 0. 004 μmol/L.With good selectivity,stability and reusability,the proposed method was successfully used in the detection of BPA in river water,milk and plastic bottles.The recoveries ranged from 98. 4%to 103%,with relative standard deviations(RSD)of 3. 4%-4. 4%.更多还原