高效的表面衍生近红外电致发光量子点的计时电位法制备及其超灵敏芯片基离子
时间:2018-04-03 21:31 来源:毕业论文 作者:毕业论文 点击:次
| 摘要本工作通过流体动力学计时电位法制备了一种新颖的具有近红(near-infrared，NIR)电致化学发光(electrochemiluminescence，ECL)特性的量子点(quantumdot，QD)，该半导体纳米晶体以一种临床用金属解毒剂Unithiol作为封端包被物并基于该发光体构建了一个超灵敏离子选择性微芯片。该QD的合成路径及其光性质由形貌和光谱学表征手段加以阐明。在空气饱和的pH 8.0的磷酸盐缓冲溶液中，以溶解氧作为内源性共反应物，一个强烈的NIR-ECL发光在692 nm处出现。这归因于该多齿螯合QDs独特的表面状态。通过调谐电解质，可进一步在−0.79 V(vs. Ag/AgCl)的低电位呈现ECL发射峰。基于证实了的重金属阳离子对稳定剂的竞争，该ECL辐射可被显著淬灭，一个自制的ECL离子选择性芯片因此得以制造。进一步发现，阳离子交换膜的覆盖可加速金属离子的吸附并敏化ECL信号。以铜离子作为典型分析物，所设计的传感器在10.0 pM至1.0 mM浓度范围内呈线性，检测下限为6.7 pM；并被成功实践于直接检测无机农药−波尔多液在葡萄皮表面的残留量，显现出较高的精度和选择性。所提议的策略也可拓展至比Cd2+有更强巯基结合能力的Hg2+和Pb2+的定量检测。所开发的微传感系统及有重现性的单步合成法应有利于便携、集成化的QD基NIR-ECL在食品卫生检验和环境监测中的应用。20557 关键词 计时电位法 离子选择性 毕业设计说明书（论文）外文摘要 Title Chronopotentiometric Synthesis of Quantum Dots With Efficient,Surface-Derived,Near-Infrared Electrochemiluminescence For Ultrasensitive Microchip-Based Ion-Selective Sensing Abstract A novel QD with near-infrared (NIR) electrochemiluminescence (ECL) emission was prepared electrolytically by hydrodynamic chronopotentiometry, using Unithiol, a clinically-known metalantidote, as the capping agent for the fabrication of an ultrasensitive ion-selective microchip. The proposed synthetic route as well as the optical properties of QD was clarified with both morphologic and spectroscopic characterizations. In air-saturated pH 8.0 phosphate buffer with dissolved oxygen as the endogenous coreactant, an intensive NIR-ECL emission at 692 nm arose which was ascribed to the unique surface states of multidentate-chelated QDs. By tuning electrolytes, a low-potential ECL peaking at −0.79 V (vs. Ag/AgCl) could further be achieved. Based on the validated competition of heavy metallic cations to the stabilizer, the ECL emission could be significantly quenched and a home-made ECL ion-selective chip was manufactured. It was further found that capping with cation exchange membrane enabled an accelerated adsorption of metal ions and sensitized the ECL signal. Using cupric cation as a model analyte, the devised sensor showed a linear range from 10.0 pM to 1.0 mM with a detection limit down to 6.7 pM; and was successfully practised in the direct detection of Bordeaux mixture as inorganic pesticide residue on the grape skin with high accuracy and selectivity. The proposed strategy could also be extended to quantify Hg2+ and Pb2+ with stronger thiol-bonding capability than Cd2+. The developed microsensing system with replicable one-step synthesis should facilitate the portable and integrated QD-based NIR-ECL applications for food hygiene inspection and environmental monitoring. Keywords Chronopotentiometric Synthesis Ion-Selective 目 次 1 引言 1 2 实验部分 3 2.1 实验材料与仪器 3 (责任编辑：qin) |