Wenchao Ma,Haochuan Chen,Yuhong Ma,Changwen Zhao,Wantai Yang
With fac -Ir(ppy) 3 as photoredox catalyst and ethyl 2-bromoisobutyrate (EBiB) as initiator, the homopolymerization of methyl methacrylate (MMA) in different solvents, such as N , N -dimethylformamide (DMF), acetonitrile, and anisole are run under irradiation of an LED lamp. The results show that anisole is a better solvent for the polymerization with regard to the polydispersity index (PDI). A well-controlled polymerization of poly(ethylene glycol) methyl ether methacrylate (PEGMA) is demonstrated and the clean block copolymer of PMMA- b -PPEGMA is prepared with PDI less than 1.3; however, the 2-(dimethylamino) ethyl methacrylate (DMAEMA) polymerization is poorly controlled. With the PMMA as macromolecular initiator, the block copolymer PMMA- b -PDMAEMA can be prepared with PDI around 2.0.
Yitian Huang,Dandan Zhao,Yanjie Chen,Shupei Zhang,Feng Lin,Hong Dai
Iridium (Ir) complexes have gained remarkable development momentum as candidates for electrochemiluminescence , but their poor solubility in water media greatly limited their application in ECL area. Herein, a facile nanoprecipitation method by encapsulating tris(2-phenylpyridinato)iridium (Ir(ppy) 3 ) into pluronic block copolymers for preparing water-soluble Ir(III) complexes with high ECL emission efficiency was developed. Then, with F-127@Ir(ppy) 3 as the anode emitter and g-C 3 N 4 as the cathode emitter, a new ratiometric biosensor based on transition metal complexes was developed for the first time, which was used for ultra-sensitive detection of hepatitis C virus E2 protein. Notably, the ratiometric ECL signal could be mediated by using multifunctional Nb 2 C nanosheets (Nb 2 C NSs) with excellent electrocatalytic activity and superoxide dismutase activity, so as to enhance the ECL intensity of anode and quench the response of cathode ECL. Combining Nb 2 C NSs with the antibody and the specific recognition process, the proposed ECL ratio biosensor showed good performance for E2 with a linear range from 1 × 10 −3 ng/mL to 1 × 10 2 ng/mL and a detection limit of 8.39 × 10 −4 ng/mL. The work on designing water-soluble Ir (III) complexes with pluronic block copolymer provides an ingenious approach to broaden the application of poorly soluble complexes in bioassays.
Haochuan Chen,Changwen Zhao,Ruibo Li,Yuhong Ma,Lianying Liu,Wantai Yang
A novel strategy, based on surface-initiated grafting polymerization and post-polymerization thiol-yne click chemistry, with Ir(ppy) 3 as a sole photoredox catalyst, under visible light irradiation is developed. The “livingness” of the grafting polymerization is demonstrated by the linear increase of the graft yield with irradiation time and the block grafting polymerization. Then, acetenyl groups of poly(propargyl methacrylate) (PPMA) grafting chains are reacted with pentaerythritoltetra-(3-mercaptopropionate) via the thiol-yne click reaction. The successful introduction of reactive thiol groups onto the low-density polyethylene- graft -poly(propargyl methacrylate) (LDPE- g -PPMA) films is demonstrated by Fourier transform IR (FTIR) and X-ray photoelectron spectra (XPS) spectroscopy, and the thiol-ene click reaction with N -(1-pyrenyl) maleimide.
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