In consideration of various advantages such as less harm,higher sensitivity,and deeper imaging depth,etc.,AIE materials with longwave emission are attracting extensive attention in the fields of vascular visualization...In consideration of various advantages such as less harm,higher sensitivity,and deeper imaging depth,etc.,AIE materials with longwave emission are attracting extensive attention in the fields of vascular visualization,organelle imaging,cells tracker,forensic detection,bioprobe and chemosensor,etc.In this work,a novel fluorescent(R)-PVHMA monomer with chirality and aggregation-induced emission enhancement(AEE)characteristics was acquired through enzymatic transesterification reaction basing on phenothiazine,and its[α]D25℃value was about-6.39°with a 3.08 eV bandgap calculated by the quantum calculations.Afterwards,a series of PEG-PVH1 and PEG-PVH2 copolymers with chirality feature were achieved through RAFT polymerization of the obtained(R)-PVHMA and PEGMA with various feed ratios.When the feed molar ratio of(R)-PVHMA increased from 21.5%to 29.6%,its actual molar fractions in the PEG-PVH1 and PEG-PVH2 copolymers accordingly increased from 18.1%to 25.7%.The molecular weight of PEG-PVH1 was about 2.2×10^(4) with a narrow PDI,and their kinetics estimation showed a first-order quasilinear procedure.In aqueous solution,the amphiphilic copolymers PEG-PVH could self-assemble into about 100 nm nanoparticles.In a 90%water solution of H_(2)O and THF mixture,the fluorescence intensity had the maximum value,and the emission wavelength presented at 580 and 630 nm.The investigation of cytotoxicity and cells uptake showed that PEG-PVH FONs performed outstanding biocompatibility and excellent cells absorption effects,which have great potential in bioimaging application.展开更多
Response speed is one of the most important evaluation criteria for CO2 sensors. In this work, we report an ultrafast CO2 fluorescent sensor based on poly[oligo（ethylene glycol） methyl ether methacrylate]-b-poly[N,N...Response speed is one of the most important evaluation criteria for CO2 sensors. In this work, we report an ultrafast CO2 fluorescent sensor based on poly[oligo（ethylene glycol） methyl ether methacrylate]-b-poly[N,N-diethylaminoethyl methacrylate-r-4-（2- methylacryloyloxyethylamino）-7-nitro-2,1,3-benzoxadiazole] [POEGMA-b-P（DEAEMA-r-NBDMA）], in which DEAEMA units act as the CO2-responsive segment and 4-nitrobenzo-2-oxa-l,3-diazole （NBD） is the chromophore. The micelles composed of this copolymer could disassemble in 2 s upon CO2 bubbling, accompanying with enhanced fluorescence emission with bathochromic shift. Furthermore, the quantum yield of the NBD chromophore increases with both the CO2 aeration time and the NBD content. Thus we attribute the fluorescent enhancement to the inhibition of the photo-induced electron transfer between unprotonated tertiary amine groups and NBD fluorophores. The sensor is durable although it is based on ＂soft＂ materials. These micellar sensors could be facilely recycled by alternative CO2/Ar purging for at least 5 times, indicating good reversibility.展开更多
基金financially supported by the Natural Science Foundation of Guangdong Province(Nos.2018A030313784 and 2021A1515410008)the Colleges and Universities Projects of Guangdong Province(Nos.2020KTSCX180,2020KTSCX184 and 2020ZDZX3027)+1 种基金the National Natural Science Foundation of China(No.51673107)the Climbing Plan of Guangdong Province(No.PDJH2021a0616)。
文摘In consideration of various advantages such as less harm,higher sensitivity,and deeper imaging depth,etc.,AIE materials with longwave emission are attracting extensive attention in the fields of vascular visualization,organelle imaging,cells tracker,forensic detection,bioprobe and chemosensor,etc.In this work,a novel fluorescent(R)-PVHMA monomer with chirality and aggregation-induced emission enhancement(AEE)characteristics was acquired through enzymatic transesterification reaction basing on phenothiazine,and its[α]D25℃value was about-6.39°with a 3.08 eV bandgap calculated by the quantum calculations.Afterwards,a series of PEG-PVH1 and PEG-PVH2 copolymers with chirality feature were achieved through RAFT polymerization of the obtained(R)-PVHMA and PEGMA with various feed ratios.When the feed molar ratio of(R)-PVHMA increased from 21.5%to 29.6%,its actual molar fractions in the PEG-PVH1 and PEG-PVH2 copolymers accordingly increased from 18.1%to 25.7%.The molecular weight of PEG-PVH1 was about 2.2×10^(4) with a narrow PDI,and their kinetics estimation showed a first-order quasilinear procedure.In aqueous solution,the amphiphilic copolymers PEG-PVH could self-assemble into about 100 nm nanoparticles.In a 90%water solution of H_(2)O and THF mixture,the fluorescence intensity had the maximum value,and the emission wavelength presented at 580 and 630 nm.The investigation of cytotoxicity and cells uptake showed that PEG-PVH FONs performed outstanding biocompatibility and excellent cells absorption effects,which have great potential in bioimaging application.
基金financially supported by the National Natural Science Foundation of China (Nos. 51573086 and 21374058)the Opening Project of State Key Laboratory of Polymer Materials Engineering (Sichuan University) (No. sklpme2014-4-26)
文摘Response speed is one of the most important evaluation criteria for CO2 sensors. In this work, we report an ultrafast CO2 fluorescent sensor based on poly[oligo（ethylene glycol） methyl ether methacrylate]-b-poly[N,N-diethylaminoethyl methacrylate-r-4-（2- methylacryloyloxyethylamino）-7-nitro-2,1,3-benzoxadiazole] [POEGMA-b-P（DEAEMA-r-NBDMA）], in which DEAEMA units act as the CO2-responsive segment and 4-nitrobenzo-2-oxa-l,3-diazole （NBD） is the chromophore. The micelles composed of this copolymer could disassemble in 2 s upon CO2 bubbling, accompanying with enhanced fluorescence emission with bathochromic shift. Furthermore, the quantum yield of the NBD chromophore increases with both the CO2 aeration time and the NBD content. Thus we attribute the fluorescent enhancement to the inhibition of the photo-induced electron transfer between unprotonated tertiary amine groups and NBD fluorophores. The sensor is durable although it is based on ＂soft＂ materials. These micellar sensors could be facilely recycled by alternative CO2/Ar purging for at least 5 times, indicating good reversibility.
