Anodic electrochemiluminescence of CdTe quantum dots and its energy transfer for detection of catechol derivatives
Anodic electrochemiluminescence of CdTe quantum dots and its energy transfer for detection of catechol derivatives
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CdTe量子点阳极电化学发光及其能量转移检测儿茶酚衍生物
DOI：
10.1021/ac070927i
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发表时间：
2007-11-01
影响因子：
7.4
通讯作者：
Ju, Huangxian
中科院分区：
文献类型：
--
作者：
Liu, Xuan;Jiang, Hui;Ju, Huangxian
首次报道了水溶液体系中CdTe量子点的阳极电化学发光（ECL）及其在分析中的应用。用巯基丙酸对CdTe量子点进行修饰，得到了水溶性的量子点，并在氧化铟锡（ITO）电极上得到了稳定而强烈的阳极电化学发光，在pH 9.3的PBS溶液中，其峰值为+1.17 V（vsAg/AgCl）。实验结果表明，ITO表面产生的超氧阴离子参与了ECL的发射过程，它可以将一个电子注入CdTe的1 Se量子限制轨道，形成量子点阴离子。这些阴离子与量子点的氧化产物发生碰撞，导致量子点激发态的形成和电致发光发射。从激发的CdTe量子点的ECL能量转移到淬灭剂产生了一种新的方法来检测邻苯二酚衍生物。使用多巴胺和L-肾上腺素作为模型分析物，这种ECL方法显示出宽的线性范围从50 nM至5 μ M和80 nM至30 μ M的这些物种。抗坏血酸和尿酸是常见的干扰物，但对实际生物样品中邻苯二酚衍生物的检测无干扰。
This work reported for the first time the anodic electrochemiluminescence (ECL) of CdTe quantum dots (QDs) in aqueous system and its analytical application based on the ECL energy transfer to analytes. The CdTe QDs were modified with mercaptopropionic acid to obtain water-soluble QDs and stable and intensive anodic ECL emission with a peak value at +1.17 V (vs Ag/AgCl) in pH 9.3 PBS at an indium tin oxide (ITO) electrode. The ECL emission was demonstrated to involve the participation of superoxide ion produced at the ITO surface, which could inject an electron into the 1Se quantum-confined orbital of CdTe to form QDs anions. The collision between these anions and the oxidation products of QDs led to the formation of the excited state of QDs and ECL emission. The ECL energy transfer from the excited CdTe QDs to quencher produced a novel methodology for detection of catechol derivatives. Using dopamine and L-adrenalin as model analytes, this ECL method showed wide linear ranges from 50 nM to 5 mu M and 80 nM to 30 mu M for these species. Both ascorbic acid and uric acid, which are common interferences, did not interfere with the detection of catechol derivatives in practical biological samples.