Hierarchical Self-Assembly of Discrete Organoplatinum(II) Metallacycles with Polysaccharide via Electrostatic Interactions and Their Application for Heparin Detection
Hierarchical Self-Assembly of Discrete Organoplatinum(II) Metallacycles with Polysaccharide via Electrostatic Interactions and Their Application for Heparin Detection
复制标题
通过静电相互作用离散有机铂(II)金属环与多糖的分层自组装及其在肝素检测中的应用
DOI：
10.1021/jacs.5b06565
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发表时间：
2015-09-16
影响因子：
15
通讯作者：
Yang, Hai-Bo
中科院分区：
文献类型：
--
作者：
Chen, Li-Jun;Ren, Yuan-Yuan;Yang, Hai-Bo
近年来，利用分级自组装技术构建人工功能材料的研究引起了人们的广泛关注。基于配位键的离散金属配合物已被证明是通过分级自组装制备各种超分子聚合物或智能软物质的有效支架。在这里，我们提出的第一个例子的分层自组装的离散金属配合物，利用有机铂（II）金属配合物骨架的正电荷，通过多个静电相互作用。肝素是一种广泛用作抗凝药物的硫酸化糖胺聚糖聚合物，由于其具有多个负电荷，因此被选择用于诱导分级自组装。为了研究分级自组装过程，通过配位驱动的自组装将聚集诱导发射（AIE）活性部分四苯乙烯（TPE）引入到金属配合物上。光物理研究表明，肝素加入到tris-TPE金属配合物溶液中导致显著的荧光增强，这支持了金属配合物和肝素之间由多重静电相互作用驱动的聚集。此外，通过SEM，TEM和LSCM实验检测到，通过分级自组装获得了缠结的珍珠项链网络。特别地，在AFM和TEM图像中观察到单个珠状链，这为带正电荷的金属酸和带负电荷的肝素的聚集提供了直接的、视觉的证据。更有趣的是，进一步的光学研究表明，这种TPE修饰的金属酸可以作为一个高灵敏度和高选择性的肝素检测荧光探针。因此，本研究提出了第一个例子的反聚阴离子诱导的分层自组装的离散金属，并提供了一个“证明的原则”的方法肝素传感和绑定。
In recent past years, investigation of hierarchical self-assembly for constructing artificial functional materials has attracted considerable attention. Discrete metallacydes based on coordination bonds have proven to be valid scaffolds to fabricate various supra-molecular polymers or smart soft matter through hierarchical self-assembly. Here, we present the first example of the hierarchical self-assembly of discrete metallacydes by taking advantage of the positive charges of the organoplatinum(II) metallacyde skeleton through multiple electrostatic interactions. Heparin, a sulfated glycosaminoglycan polymer that has been widely used as an anticoagulant drug, was selected to induce hierarchical self-assembly because of the existence of multiple negative charges. To investigate the hierarchical self-assembly process, an aggregation-induced emission (AIE) active moiety, tetra-phenylethylene (TPE), was introduced onto the metallacyde via coordination-driven self-assembly. Photophysical studies revealed that the addition of heparin to the tris-TPE metallacydes solution resulted in dramatic fluorescence enhancement, which supported the aggregation between metallacycle and heparin driven by multiple electrostatic interactions. Moreover, the entangled pearl-necklace networks were obtained through hierarchical self-assembly as detected by SEM, TEM, and LSCM experiments. In particular, single bead-like chains were observed in the AFM and TEM images, which provided direct, visual evidence for the aggregation of positively charged metallacydes and negatively charged heparin. More interestingly, further optical study demonstrated that this TPE-decorated metallacyde could function as a turn-on fluorescent probe for heparin detection with high sensitivity and selectivity. Thus, this research presents the first example of counter polyanion-induced hierarchical self-assembly of discrete metallacydes and provides a "proof-of-principle" method for heparin sensing and binding.