【作者】 陈沁；

【导师】 钱和；

【作者基本信息】 江南大学 ， 营养与食品卫生， 2009， 硕士

【摘要】 溴酸盐是2B级潜在致癌物,主要存在于天然矿泉水和面制品中。目前采用的检测方法都是离子色谱法,仪器昂贵,不适合普遍推广使用,无法满足实时在线检测。因此,研究和建立一种方便、安全和快速的检测方法具有重要意义。化学修饰电极是通过化学修饰的方法在电极表面进行分子设计,将具有优良物理化学性质的分子、离子、聚合物固定在电极表面,从而具有某种特定的化学和物理性质的一类电极。其应用已涉及到化学、生命科学、医学、环境、食品和军事等诸多领域。本论文主要内容包括利用电化学的特性,制备新型快速灵敏的溴酸盐电化学传感器,建立溴酸盐快速检测方法,并对实际样品进行测定。具体研究结果如下:采用电聚合的方法制备GC/Ppy/PMo₁₂纳米复合修饰电极,通过循环伏安法（CV）对电极化学性质进行表征,发现Ppy大大的改善PMo₁₂的化学性质和对BrO₃^-的电催化还原效应。该修饰电极在0.5 mol/L H₂SO₄中有着良好的电化学行为。在﹣0.06 V的检测电位下,采用I—T曲线法,发现该修饰电极在溴酸盐浓度为0.005-0.1 mmol/L的范围内有着良好的线性关系,相关系数为0.998,响应时间为1.87 s,最低检测限为2μmol/L,灵敏度为46.86μA·mmol^-1·L·cm^-2。基于层层组装法,将带正电荷的PDDA和带负电荷的功能化的MWNTs通过静电吸引力的作用构筑{MWNTs/PDDA}n/PMo₁₂修饰电极。通过SEM、UV-Vis技术对该修饰电极的微观形貌进行表征。通过电化学方法研究表明该电极对溴酸盐有着良好的电催化性能。优化组装层数、溶液pH值以及PMo₁₂的使用量。在最佳的实验条件下,检测电位为﹣0.09 V,{MWNTs/PDDA}₅/PMo₁₂修饰电极在溴酸盐浓度为0.05-0.4μmol/L的范围内有着良好的线性关系,相关系数为0.99,响应时间为1.53 s,最低检测限为0.02μmol/L,灵敏度为966.9μA·mmol^-1·L·cm^-2。结果表明,该修饰电极的BrO₃^-传感器表现出较Gc/Ppy/PMo₁₂修饰电极卓越的性能。使用{MWNTs/PDDA}₅/PMo₁₂修饰电极对实际样品进行检测,结果表明该电极具有良好的重现性和稳定性。更多还原

【Abstract】 Bromates are 2B-class potential carcinogens, which are mainly found in natural mineral water and flour goods. Tranditional Method currently used to detect bromates is ion chromatography. Due to the expensive cost of equipments, it cannot be widely applied in real-time detection. Therefore, it is meaningful to establish a convenient, safe and rapid detection method for bromates. Owing to their present particular physical and chemical properties via surface bonding of certain molecules, ions or polymers, chemically modified electrodes have been widely employed in many fields such as chemistry, biology, medicine, environment, food and military. The aim of present research is to prepare new bromate electrochemical sensors with fast and accurate responses. The main research contents are as follows:Gc/Ppy/PMo₁₂ modified electrodes were prepared using electropolymerization. On the bais of cyclic voltammetry （CV） experimental results, it was found that Ppy significantly improved chemical properties of PMo₁₂ and its electro-catalytic reducibility to BrO₃^-. In 0.5 mol/L H2SO4 solution, the modified electrode presented good electrochemical behavior.Under the detecting potential -0.05 V.,using I-T surve method, in the concentration range of 0.005-0.1 mmol/L ,the linear correlation coefficient was 0.998, the response time was 1.87 s, its detection limit on bromate was 2μmol/L, and sensitivity was 46.86μA·mmol^-1·L·cm^-2.In this chapter , layer-by-layer{MWNTs/PDDA}n/PMo₁₂ films assembled by altematead sorption of positively charged PDDA and negatively charged funditional MWNTs onto a glassy carbon electrode.The micorstructure of modified electrode were characterized by SEM and UV-Vis. Electric properties of the modified electrode were investigated by CV method and displayed a good electrocatalytic activity to the reduction of broamte . Lay numbers , pH and the concentration of PMo₁₂ were optimized. At -0.09V, in the range of 0.05-0.4μmol/L, the linear correlation coefficient was 0.99, the response time was 1.53 s, its detection limit on BrO₃^- was 0.02μmol/L, and the sensitivity was 966.9μA·mmol^-1·L·cm^-2. The result displayed that the electrode prepared by this method had a superior performance than that of Gc/Ppy/PMo₁₂.The experimental resulted on commercial goods using {MWNTs/PDDA}₅/PMo₁₂ modified electrode indicated that the modified electrode had good reproducibility and stability.更多还原