Cyclometalated Iridium-Complex-Based Label-Free Supersandwich Electrogenerated Chemiluminescence Biosensor for the Detection of Micro-RNA
Cyclometalated Iridium-Complex-Based Label-Free Supersandwich Electrogenerated Chemiluminescence Biosensor for the Detection of Micro-RNA
复制标题
基于环金属铱配合物的无标记超三明治电致化学发光生物传感器用于检测 Micro-RNA
DOI：
10.1002/celc.201600881
复制
发表时间：
2017
期刊：
影响因子：
4
通讯作者：
Zhang Chengxiao
中科院分区：
文献类型：
--
作者：
Zhao Ying;Yang Xiaolin;Han Danjuan;Qi Honglan;Gao Qiang;Zhang Chengxiao
作为电致化学发光(ECL)试剂的化合物的合成和表征是ECL生物传感器基础研究的关键。本工作以2-苯基苯并噻唑(Bt)为主配体，5，6-二甲基-1，10-菲咯啉(Dmphen)为辅助配体，合成了一种新的环金属Ir(III)配合物[(Bt)2Ir(Dmphen)](PF6)。研究了该配合物在乙腈溶剂和水溶液中的光物理、电化学性质和电致发光性质。该络合物的最大发光波长为522 nm，在E_1/2=+1.51 V(vs.SCE)处有一个可逆单电子氧化波，在−_(1.29) V(vs.SCE)处有一个可逆单电子还原波。典型地，在湮没过程中，该配合物的ECL效率是Ru(Bpy)32+的12倍。更重要的是，基于该络合物作为电致发光嵌入剂和信号放大的超Sandwich模型，建立了一种高灵敏的亚皮摩尔水平的电致发光测定微量RNA的方法。与Ru(Phen)3Cl2和[(Bt)2Ir(Dcbpy)](PF6)相比，在所开发的体系中，该配合物具有相对较低的背景和最高的ECL插层率。在0.1~10 pm范围内，电致发光强度的增加与微量核糖核酸的浓度成正比，检测下限为13 fM。该方法能有效区分靶标microRNA122和两个碱基错配的microRNA122。这项工作表明，这种环金属Ir(III)络合物是一种有效的电化学发光测定微量RNA的替代嵌入剂。预计这种复合体将被扩展到设计各种分析平台，用于检测不同的分析物，如DNA/RNA、DNAzyme/靶标和适体/靶标。
The synthesis and characterization of compounds as electrogenerated chemiluminescence (ECL) reagents are crucial in fundamental research for ECL biosensors. In this work, a new cyclometalated iridium(III) complex, [(bt)2Ir(dmphen)](PF6), was synthesized by using 2‐phenylbenzothiazole (bt) as the main ligand and 5,6‐dimethyl‐1,10‐phenanthroline (dmphen) as the ancillary ligand. The photophysical, electrochemical, and ECL properties of this complex were extensively studied in acetonitrile solvent and aqueous solution. This complex displayed yellow‐green photoluminescence with a maximum wavelength at 522 nm, a reversible one‐electron oxidation wave atE1/2=+1.51 V (vs. SCE), and a reversible one‐electron reduction wave at −1.29 V (vs. SCE). Typically, in the annihilation process, the ECL efficiency of this complex was 12 times higher than that of Ru(bpy)32+. More importantly, a highly sensitive ECL method for the determination of micro‐RNA at the sub‐picomolar level was developed on basis of employing this complex as an ECL intercalator and signal amplification by using the supersandwich model. Compared with Ru(phen)3Cl2and [(bt)2Ir(dcbpy)](PF6), this complex showed a relatively low background and the highest increased ratio as an ECL intercalator in the developed system. The increased ECL intensity was directly proportional to the concentration of the micro‐RNA in the range of 0.1 to 10 pM, with a detection limit of 13 fM. The developed method can effectively discriminate target micro‐RNA122 from two‐base mismatched micro‐RNA122. This work demonstrates that this cyclometalated iridium(III) complex is an effective alternative intercalator for ECL determination of the micro‐RNA. It is expected that this complex will be extended to design various analytical platforms for the detection of diverse analytes such as DNA/RNA, DNAzyme/target, and aptamer/targets.