Institute of Analytical Chemistry, Department of Chemistry, Soochow University, Dushu Lake Higher Education Town, Suzhou Industrial Park, Suzhou, 215123, PR China.
Talanta. 2012 May 30;94:289-94. doi: 10.1016/j.talanta.2012.03.042. Epub 2012 Mar 29.
A microemulsion enhanced electrochemiluminescence (ECL) of luminol-H(2)O(2) was studied with the flow-injection (FI) technique. The results revealed that the microemulsion composed with cetyltrimethylammonium bromide (CTAB), n-butanol, n-heptane and water greatly enhanced the ECL especially in acidic medium. The ECL emission increased for 20 to 2 times in this microemulsion medium over the pH range of 5.0-8.0 compared to that in aqueous solution. The mechanism of enhancement of surfactant and microemulsion for luminol-H(2)O(2) ECL was discussed. It is mainly based on the electrostatic interaction between luminol anion and the head group of surfactant, which causes the adsorption and promotes the dissociation of luminol on the surfaces of the microemulsion droplets, favors the oxidation of luminol by the yielded reactive oxygen species (ROSs) during electrolysis. This research is very significant for ECL applications because of the extended practicable pH range which was suitable for environmental and biological systems. As an example, this FI-ECL technique can be applied for determination of oligo proanthocyanidin (OPC) because of its antioxidant property and to evaluate the total antioxidant activity of the grape skin using OPC as an index.
研究了以流动注射（FI）技术为基础的微乳液增强鲁米诺-H（2）O（2）电化学发光（ECL）。结果表明，由十六烷基三甲基溴化铵（CTAB）、正丁醇、正庚烷和水组成的微乳液极大地增强了 ECL，特别是在酸性介质中。与在水溶液中相比，在 pH 值为 5.0-8.0 的范围内，该微乳液介质中的 ECL 发射强度增加了 20 到 2 倍。讨论了表面活性剂和微乳液对鲁米诺-H（2）O（2）ECL 增强的机理。这主要基于鲁米诺阴离子与表面活性剂的头基之间的静电相互作用，导致鲁米诺在微乳液液滴表面的吸附和促进其解离，有利于在电解过程中由生成的活性氧物质（ROSs）氧化鲁米诺。由于扩展的实际 pH 范围适用于环境和生物系统，因此这项研究对于 ECL 的应用非常重要。例如，这种 FI-ECL 技术可用于测定低聚原花青素（OPC），因为其具有抗氧化特性，并可使用 OPC 作为指标来评估葡萄皮的总抗氧化活性。
