We investigated a novel water-soluble conjugated polymer （WSCP） for thiol detection based on ＂turn-off＂ ef- fect. This WSCP was modified with poly（ethylene glycol） （PEG） by disulfide linkages to achieve good s...We investigated a novel water-soluble conjugated polymer （WSCP） for thiol detection based on ＂turn-off＂ ef- fect. This WSCP was modified with poly（ethylene glycol） （PEG） by disulfide linkages to achieve good solubility in aqueous solution （34 mg/mL） and high quantum yield （0.47）. The separation of water-soluble PEG chains from the conjugated backbone induced by the cleavage of the disulfide linkages would lead to a significant decrease of the water solubility and a dramatical fluorescence quenching of the probe. The combined intuitive images and fluores- cence spectrophotometer further confirmed that decreased solubility produced an aggregation of the hydrophobic conjugated backbone. The fluorescence intensity of the probe showed a good linear relationship with glutathione （GSH） （1-200 nmol·L^-1）, and the detection limit was 16 nmol·L^-1. This WSCP probe was confirmed to be a good sensing material with high selectivity to thiols by testing various biological molecules. And this WSCP probe ex- hibited good detection effect to intracellular thiols by testing Hela cells. Considering the good sensitivity and selec- tivity, the probe could be further used in vivo. In conclusion, this conjugated polymer probe made up for the draw- backs of the micromolecue probes and contributed to the development of new probes based on conjugated poly- mers.展开更多
An anionic water-soluble polyfluorene derivative, poly(9,9-bis(6′-phosphatehexyl)fluorene-alt-1,4-pheny lene) sodium salt (PFHPNa), was synthesized by Suzuki coupling reaction in DMF/water. Polymer PFHPNa was well so...An anionic water-soluble polyfluorene derivative, poly(9,9-bis(6′-phosphatehexyl)fluorene-alt-1,4-pheny lene) sodium salt (PFHPNa), was synthesized by Suzuki coupling reaction in DMF/water. Polymer PFHPNa was well soluble in water with a strong blue fluorescence emission. Effect of the side chain length on fluorescence sensory properties was studied by comparing quenching efficiencies toward different quenchers of PFHPNa with a reported polymer poly(9,9-bis(3′-phosphatepropyl)fluorene-alt-1,4-phenylene) sodium salt (PFPPNa), which have different side chains in length. For small molecular quenchers (methylviologen, MV2+) and meso-5,10,15,20-tetrakis-(N-methyl-4-pyridyl)porphine (TMPyP4), polymer PFHPNa had lower sensitivity due to the much longer side chain length. The positively charged metalloprotein cytochrome c could quench fluorescence of conjugated polymers via energy transfer and electron transfer. Moreover, polymer PFHPNa showed higher fluorescence quenching toward large biomolecules than PFPPNa. The corresponding Stern-Volmer (Ksv) value of polymer PFHPNa was determined to be 2.1×108 M-1 for cytochrome c. It could be used as a sensitive and selective fluorescence sensor for protein cytochrome c.展开更多
Insulated molecular wires of poly(phenylenevinylene) (PPV) were prepared by wrapping the conjugated backbones with dendrons through a noncovalent approach. It was found that electrostatic interaction between the quate...Insulated molecular wires of poly(phenylenevinylene) (PPV) were prepared by wrapping the conjugated backbones with dendrons through a noncovalent approach. It was found that electrostatic interaction between the quaternary ammonium groups of PPV-1 and the carboxylate moieties in dendrons induced the packing of dendrons along PPV-1 conjugated backbones. Absorption and emission spectroscopic examinations in solution and solid film indicated that the PPV-1 backbones adopted a more planar and isolated conformation in the complexes. Furthermore, interchain interactions in the complexes could be greatly reduced, improving the quantum yield of PPV-1.展开更多
A novel crosslinkable water/alcohol soluble conjugated polymer PFN-C containing oxetane groups and aminoalkyl groups in the side chains has been developed and used as highly efficient electron injection and transporti...A novel crosslinkable water/alcohol soluble conjugated polymer PFN-C containing oxetane groups and aminoalkyl groups in the side chains has been developed and used as highly efficient electron injection and transporting material for polymer light-emitting diodes (PLEDs). The unique solubility in polar solvents and crosslinkable ability of PFN-C render it a good can- didate for solution processed multilayer PLEDs. It was found that PFN-C can greatly enhance the electron injection from high work-function metal cathode, due to its pendant amino groups. As a result, PLEDs with PFN-C/Al cathode exhibited compara- ble device performance to the devices with Ba/Al cathode. The resulting green light-emitting device showed promising perfor- mance with a maximum luminance efficiency of 13.53 cd A-1.展开更多
文摘We investigated a novel water-soluble conjugated polymer （WSCP） for thiol detection based on ＂turn-off＂ ef- fect. This WSCP was modified with poly（ethylene glycol） （PEG） by disulfide linkages to achieve good solubility in aqueous solution （34 mg/mL） and high quantum yield （0.47）. The separation of water-soluble PEG chains from the conjugated backbone induced by the cleavage of the disulfide linkages would lead to a significant decrease of the water solubility and a dramatical fluorescence quenching of the probe. The combined intuitive images and fluores- cence spectrophotometer further confirmed that decreased solubility produced an aggregation of the hydrophobic conjugated backbone. The fluorescence intensity of the probe showed a good linear relationship with glutathione （GSH） （1-200 nmol·L^-1）, and the detection limit was 16 nmol·L^-1. This WSCP probe was confirmed to be a good sensing material with high selectivity to thiols by testing various biological molecules. And this WSCP probe ex- hibited good detection effect to intracellular thiols by testing Hela cells. Considering the good sensitivity and selec- tivity, the probe could be further used in vivo. In conclusion, this conjugated polymer probe made up for the draw- backs of the micromolecue probes and contributed to the development of new probes based on conjugated poly- mers.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 20574067 & 50633040)the Science Fund for Creative Research Groups (Grant No. 20621401)the 973 Project (Grant No. 2002CB613402)
文摘An anionic water-soluble polyfluorene derivative, poly(9,9-bis(6′-phosphatehexyl)fluorene-alt-1,4-pheny lene) sodium salt (PFHPNa), was synthesized by Suzuki coupling reaction in DMF/water. Polymer PFHPNa was well soluble in water with a strong blue fluorescence emission. Effect of the side chain length on fluorescence sensory properties was studied by comparing quenching efficiencies toward different quenchers of PFHPNa with a reported polymer poly(9,9-bis(3′-phosphatepropyl)fluorene-alt-1,4-phenylene) sodium salt (PFPPNa), which have different side chains in length. For small molecular quenchers (methylviologen, MV2+) and meso-5,10,15,20-tetrakis-(N-methyl-4-pyridyl)porphine (TMPyP4), polymer PFHPNa had lower sensitivity due to the much longer side chain length. The positively charged metalloprotein cytochrome c could quench fluorescence of conjugated polymers via energy transfer and electron transfer. Moreover, polymer PFHPNa showed higher fluorescence quenching toward large biomolecules than PFPPNa. The corresponding Stern-Volmer (Ksv) value of polymer PFHPNa was determined to be 2.1×108 M-1 for cytochrome c. It could be used as a sensitive and selective fluorescence sensor for protein cytochrome c.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 20604013, 20774056, and 50533030)
文摘Insulated molecular wires of poly(phenylenevinylene) (PPV) were prepared by wrapping the conjugated backbones with dendrons through a noncovalent approach. It was found that electrostatic interaction between the quaternary ammonium groups of PPV-1 and the carboxylate moieties in dendrons induced the packing of dendrons along PPV-1 conjugated backbones. Absorption and emission spectroscopic examinations in solution and solid film indicated that the PPV-1 backbones adopted a more planar and isolated conformation in the complexes. Furthermore, interchain interactions in the complexes could be greatly reduced, improving the quantum yield of PPV-1.
基金financially supported by the Natural Science Foundation of China (50990065, 51010003, 51073058 & 20904011)the National Basic Research Program of China (973 Program, 2009CB623601)the Fun-damental Research Funds for the Central Universities, South China Uni-versity of Technology
文摘A novel crosslinkable water/alcohol soluble conjugated polymer PFN-C containing oxetane groups and aminoalkyl groups in the side chains has been developed and used as highly efficient electron injection and transporting material for polymer light-emitting diodes (PLEDs). The unique solubility in polar solvents and crosslinkable ability of PFN-C render it a good can- didate for solution processed multilayer PLEDs. It was found that PFN-C can greatly enhance the electron injection from high work-function metal cathode, due to its pendant amino groups. As a result, PLEDs with PFN-C/Al cathode exhibited compara- ble device performance to the devices with Ba/Al cathode. The resulting green light-emitting device showed promising perfor- mance with a maximum luminance efficiency of 13.53 cd A-1.
