Jia Dehao, Hua Yunhui, Wu Tingting, Ren Xiang, Gao Xing, Yang Lei, Wei Qin
College of Biological and Chemical Engineering, Qilu Institute of Technology, Jinan, 250200, PR China; Key Laboratory of Interfacial Reaction & Sensing Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022, PR China.
Key Laboratory of Interfacial Reaction & Sensing Analysis in Universities of Shandong, School of Chemistry and Chemical Engineering, University of Jinan, Jinan, 250022, PR China.
Anal Chim Acta. 2025 Mar 1;1341:343639. doi: 10.1016/j.aca.2025.343639. Epub 2025 Jan 15.
The development of aggregation-induced emission (AIE) luminophores is a fascinating and promising topic in electrochemiluminescence (ECL) bioanalysis. Herein, the AIE-active but water-insoluble [Ir(bt)₂(acac)] (bt = 2-phenylbenzothiazole, acac = acetylacetonate) was encapsulated within poly(styrene-maleic anhydride) (PSMA) using a simple nanoprecipitation method. This encapsulation strategy could effectively limit the free motion of Ir(bt)₂(acac) and trigger the aggregation-induced electrochemiluminescence (AIECL) effect. The water dispersibility and ECL intensity of Ir(bt)₂(acac)-polymer dots (IrPdots) were greatly improved compared to equivalent amounts of Ir(bt)₂(acac) alone. More importantly, unlike Ir(bt)₂(acac), the IrPdots possess carboxyl groups, allowing them to be conjugated with biomolecules for bioanalytical applications. Consequently, a sandwich ECL immunosensor for the sensitive detection of CD44 was constructed using the prepared IrPdots-labeled detection antibody (Ab) as the ECL probe and polyaniline nanorods (PANI NRs) as the substrate that provided a large electroactive surface for immobilizing capture antibody (Ab). Under optimized experimental conditions, a good linear relationship was observed between the logarithm of ECL intensity and the CD44 concentration, ranging from 0.1 pg/mL to 50 ng/mL, with a detection limit as low as 77 fg/mL. This work introduces a method for the preparation of Pdots containing AIE-active cyclometallated iridium complexes, potentially broadening the application of these water-insoluble but highly AIE-active iridium complexes in aqueous bioassays.
聚集诱导发光（AIE）发光体的发展是电化学发光（ECL）生物分析中一个引人入胜且前景广阔的课题。在此，采用简单的纳米沉淀法将具有AIE活性但水不溶性的[Ir(bt)₂(acac)]（bt = 2-苯基苯并噻唑，acac = 乙酰丙酮）封装在聚（苯乙烯-马来酸酐）（PSMA）中。这种封装策略可以有效地限制Ir(bt)₂(acac)的自由运动并触发聚集诱导电化学发光（AIECL）效应。与等量的单独的Ir(bt)₂(acac)相比，Ir(bt)₂(acac)-聚合物点（IrPdots）的水分散性和ECL强度得到了极大的提高。更重要的是，与Ir(bt)₂(acac)不同，IrPdots具有羧基，使其能够与生物分子共轭用于生物分析应用。因此，使用制备的IrPdots标记的检测抗体（Ab）作为ECL探针，聚苯胺纳米棒（PANI NRs）作为为固定捕获抗体（Ab）提供大电活性表面的底物，构建了用于灵敏检测CD44的夹心ECL免疫传感器。在优化的实验条件下，观察到ECL强度的对数与CD44浓度之间在0.1 pg/mL至50 ng/mL范围内具有良好的线性关系，检测限低至77 fg/mL。这项工作介绍了一种制备含有AIE活性环金属化铱配合物的聚合物点的方法，有可能拓宽这些水不溶性但具有高度AIE活性的铱配合物在水性生物分析中的应用。
