title: Hierarchical Self-Assembly of Discrete Organoplatinum(II) Metallacycles with Polysaccharide via Electrostatic Interactions and Their Application for Heparin Detection.
abstract: In recent past years, investigation of hierarchical self-assembly for constructing artificial functional materials has attracted considerable attention. Discrete metallacycles based on coordination bonds have proven to be valid scaffolds to fabricate various supramolecular polymers or smart soft matter through hierarchical self-assembly. Here, we present the first example of the hierarchical self-assembly of discrete metallacycles by taking advantage of the positive charges of the organoplatinum(II) metallacycle 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 metallacycle via coordination-driven self-assembly. Photophysical studies revealed that the addition of heparin to the tris-TPE metallacycles 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 metallacycles and negatively charged heparin. More interestingly, further optical study demonstrated that this TPE-decorated metallacycle 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 metallacycles and provides a "proof-of-principle" method for heparin sensing and binding.
authors: Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University , Shanghai 200062, PR China.
authors: Li-Jun
authors: LJ
authors: Chen
authors: Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University , Shanghai 200062, PR China.
authors: Yuan-Yuan
authors: YY
authors: Ren
authors: Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University , Shanghai 200062, PR China.
authors: Nai-Wei
authors: NW
authors: Wu
authors: Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University , Shanghai 200062, PR China.|Department of Chemistry and Biochemistry & Materials Science, Engineering, and Commercialization Program, Texas State University , San Marcos, Texas 78666, United States.
authors: Bin
authors: B
authors: Sun
authors: Department of Chemistry, Beijing Normal University , Beijing 100050, PR China.
authors: Jian-Qiu
authors: JQ
authors: Ma
authors: Key Laboratory of Colloid, Interface and Chemical Thermodynamics, Institute of Chemistry, The Chinese Academy of Sciences , Beijing, 100080, PR China.
authors: Li
authors: L
authors: Zhang
authors: Department of Chemistry, Beijing Normal University , Beijing 100050, PR China.
authors: Hongwei
authors: H
authors: Tan
authors: Key Laboratory of Colloid, Interface and Chemical Thermodynamics, Institute of Chemistry, The Chinese Academy of Sciences , Beijing, 100080, PR China.
authors: Minghua
authors: M
authors: Liu
authors: Department of Chemistry and Biochemistry & Materials Science, Engineering, and Commercialization Program, Texas State University , San Marcos, Texas 78666, United States.
authors: Xiaopeng
authors: X
authors: Li
authors: Shanghai Key Laboratory of Green Chemistry and Chemical Processes, Department of Chemistry, East China Normal University , Shanghai 200062, PR China.
authors: Hai-Bo
authors: HB
authors: Yang
mesh_terms: D006493:Heparin / Q000032:analysis*; D018625:Microscopy, Atomic Force; D008855:Microscopy, Electron, Scanning; D009942:Organometallic Compounds / Q000737:chemistry*; D009944:Organoplatinum Compounds / Q000737:chemistry*; D011134:Polysaccharides / Q000737:chemistry*; D055672:Static Electricity
chemical_list: D009942:Organometallic Compounds; D009944:Organoplatinum Compounds; D011134:Polysaccharides; D006493:Heparin