Du Yu, Geng Hao, Chen Jingui, Feng Rui, Wu Tingting, Zhang Xiaoyue, Wei Qin
School of Water Conservancy and Environment, University of Jinan, Jinan 250022, P. R. China.
Key Laboratory of Interfacial Reaction & Sensing Analysis in Universities of Shandong, Collaborative Innovation Center for Green Chemical Manufacturing and Accurate Detection, School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, P. R. China.
Anal Chem. 2025 Sep 30;97(38):21060-21070. doi: 10.1021/acs.analchem.5c04283. Epub 2025 Sep 15.
The electrochemiluminescence (ECL) performance of tetraphenylethylene (TPE) derivatives benefits from their intrinsic aggregation-induced emission (AIE) characteristics. Under appropriate aggregation conditions, restricted intramolecular motion and suppressed nonradiative decay facilitate excited-state formation, thereby enhancing ECL efficiency. However, excessive molecular aggregation increases the proportion of ineffective luminescent species, which reduces the excited-state population and ultimately limits the ECL output. To address this, we report the first construction of a supramolecular organic framework (SOF) as an ECL emitter, formed via host-guest complexation between cucurbit[8]uril (CB[8]) and a carboxylated TPE derivative (TPE-4PYCOOH-4Br). The resulting SOF exhibits a 6.49-fold enhancement in ECL intensity compared to the free TPE derivative in the annihilation pathway, attributed to reduced nonradiative losses and suppressed intramolecular motion enabled by its rigid structure. Based on this enhancement, we developed a split-type ECL biosensor for matrix metalloproteinase 9 (MMP 9) detection, using a peptide-modified FeO nanosphere as a coreaction accelerator. Following MMP 9-specific cleavage, FeO nanospheres (FeO NS) become accessible to the sensing system, catalyzing triethylamine (TEA) radical generation and amplifying the ECL signal. The biosensor achieved a limit of detection (LOD) of 0.29 pg/mL, showed excellent linearity from 1 pg/mL to 50 ng/mL ( = 0.993), and demonstrated high specificity and reproducibility in serum samples. This study introduces SOFs as a new class of ECL emitters and offers an effective strategy to improve AIE-based luminophores for highly sensitive biomarker detection.
四苯乙烯（TPE）衍生物的电化学发光（ECL）性能得益于其固有的聚集诱导发光（AIE）特性。在适当的聚集条件下，分子内运动受限和非辐射衰变受到抑制，有利于激发态的形成，从而提高ECL效率。然而，过度的分子聚集会增加无效发光物种的比例，这会减少激发态粒子数并最终限制ECL输出。为了解决这个问题，我们报道了首次构建一种超分子有机框架（SOF）作为ECL发光体，它是通过葫芦[8]脲（CB[8]）与羧基化TPE衍生物（TPE-4PYCOOH-4Br）之间的主客体络合形成的。在湮灭途径中，所得的SOF与游离TPE衍生物相比，ECL强度提高了6.49倍，这归因于其刚性结构减少了非辐射损失并抑制了分子内运动。基于这种增强效果，我们开发了一种用于检测基质金属蛋白酶9（MMP 9）的分裂型ECL生物传感器，使用肽修饰的FeO纳米球作为共反应促进剂。在MMP 9特异性裂解后，传感系统可以接触到FeO纳米球（FeO NS），催化三乙胺（TEA）自由基的产生并放大ECL信号。该生物传感器的检测限（LOD）为0.29 pg/mL，在1 pg/mL至50 ng/mL范围内显示出出色的线性（ = 0.993），并且在血清样品中表现出高特异性和重现性。这项研究将SOF引入作为一类新的ECL发光体，并提供了一种有效的策略来改进基于AIE的发光体用于高灵敏度生物标志物检测。
