State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
Key Lab of Mesoscopic Chemistry of MOE and Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
Anal Chem. 2021 Jan 26;93(3):1686-1692. doi: 10.1021/acs.analchem.0c04284. Epub 2020 Dec 30.
This work developed a sensitive electrochemiluminescence (ECL) biosensor based on a cyclometalated iridium(III) complex ((bt)Irbza), which was synthesized for the first time. Annihilation, reductive-oxidative, and oxidative-reductive ECL behaviors of (bt)Irbza were investigated, respectively. The oxidative-reductive ECL intensity was the strongest compared with the other two, which showed 16.7 times relative ECL efficiency compared with commercial [Ru(bpy)] under the same experimental conditions. Therefore, an ECL biosensing system with (bt)Irbza as the anodic luminophore was established for miRNA detection based on a closed bipolar electrode (BPE). Combined with both steric hindrance and catalytic effects induced by hemin/G-quadruplex in the cathodic reservoir of BPE that changed the Faraday current of the cathode and thus mediated the ECL intensity of (bt)Irbza in the anode of BPE, the ECL sensor stated an ultrahigh sensitivity for microRNA (miRNA-122) analysis with a detection limit of 82 aM.
本工作基于首次合成的金属铱配合物((bt)Irbza)，开发了一种灵敏的电致化学发光（ECL）生物传感器。分别研究了(bt)Irbza 的湮灭、还原氧化和氧化还原 ECL 行为。与其他两种相比，氧化还原 ECL 强度最强，在相同实验条件下，与商业[Ru(bpy)]相比，相对 ECL 效率提高了 16.7 倍。因此，基于双极电极（BPE）建立了以(bt)Irbza 为阳极发光体的 ECL 生物传感系统，用于 miRNA 的检测。结合 BPE 阴极储层中血红素/G-四链体诱导的空间位阻和催化作用，改变了阴极的法拉第电流，从而调节了 BPE 阳极中(bt)Irbza 的 ECL 强度，该 ECL 传感器对微 RNA（miRNA-122）分析具有超高灵敏度，检测限低至 82 aM。
