巯基功能化有机硅纳米颗粒修饰金电极的制备及对痕量铅的测定  

Preparation of a thiol-functionalized organosilica nanoparticles modified Au electrode and its application to the detection of trace lead

作　　者：肖健林[1] 沈学静[2] 刘建允[1] 林海莲[1] 张鑫[1] 廖金金[1] 

机构地区：[1]东华大学环境科学与工程学院,上海201620 [2]钢铁研究总院分析测试研究所,北京100081

出　　处：《分析试验室》2013年第5期29-33,共5页Chinese Journal of Analysis Laboratory

基　　金：国家自然科学基金(21105009);电分析化学国家重点实验室开放课题(SKLEAC201205)资助

摘　　要：以3-巯丙基三甲氧基硅烷(MPTS)为单一硅源,十六烷基三甲基溴化铵(CTMAB)存在下,采用一步简单混合,较方便地制得均匀、小粒径的有机硅纳米颗粒。采用原子力显微镜(AFM)、透射电子显微镜(TEM)对有机硅纳米进行表征,测得粒径约为2.5 nm。通过自组装法将其固定在金电极表面,得到均匀、高巯基含量的有机硅纳米修饰电极。采用方波溶出伏安法(SWV),考察了CTMAB浓度、Bi3+浓度、支持电解质、pH值富集电位及富集时间等参数对铅溶出信号的影响。结果表明:在0.2 mol/L HAc-NaAc(pH 5.0)缓冲溶液中,-1.0V电位下富集10 min,Pb2+溶出峰电流与浓度分别在5.0～500×10-12mol/L;2.5～250×10-9 mol/L和250～1250×10-9 mol/L范围内呈线性关系,最低检出浓度为5.0×10-12mol/L。利用本方法测定了实际水样中铅的含量,并与原子荧光光谱法进行对比,结果一致。By a facile one-step synthesis route, the uniform organosilica nanoparticles with small sizes were fabricated using （ 3-mercaptopropyl ）-trimethoxysilane （ MPTS ） as a single silica source and cetyhrimethylammonium bromide （CTAB） as a template. The morphology of the organosilica nanoparticles was characterized by atomic force microscope （AFM）. The particle size was about 2. 5 nm as measured by transmission electron microscope （TEM）. By simple self-assembling, the uniform and stable organosilica-nanoparticle film modified Au electrode with high density of thiol group was obtained. Several experimental parameters such as CTAB content, Bi3 ＋ concentration, supporting electrolyte, pH values, accumulation potential and accumulation time were studied by square wave stripping vohammetry （SWV）. Under the optimized experimental conditions, the three linear ranges of 5.0 - 500 ×10^-12 mol/L, 2. 5 - 250 ×10^-9 mol/L and 250 - 1250 ×10^-9 mol/L were achieved with 10 min preconcentration atl. 0 V in 0. 2 mol/L acetic acid-sodium acetate buffer （pH 5）. The lowest detectable concentration was as low as 5. 0 ×10^-12 moL/L. The developed sensor was applied to the detection of lead in actual water and the results were concordant with those by atomic fluorescence spectrometry （AFS）.

关 键 词：3-巯丙基三甲氧基硅烷 有机硅纳米颗粒 化学修饰金电极 方波溶出伏安法 铅 

分 类 号：O657.1[理学—分析化学]