Surface chirality plays an important role in determining the biological effect,but the molecular nature beyond stereoselectivity is still unknown.Herein,through surface-enhanced infrared absorption spectroscopy,electr...Surface chirality plays an important role in determining the biological effect,but the molecular nature beyond stereoselectivity is still unknown.Herein,through surface-enhanced infrared absorption spectroscopy,electrochemistry,and theoretical simulations,we found diasteromeric monolayers induced by assembled density on chiral gold nanofilm and identified the positive contribution of water dipole poten-tial at chiral interface and their different interfacial interactions,which result in a difference both in the positive dipoles of interfacial water compensating the negative surface potential of the SAM and in the hindrance effect of interface dehydration,thereby regulating the interaction between amyloid-βpeptide(Aβ)and N-isobutyryl-cysteine(NIBC).Water on L-NIBC interface which shows stronger positive dipole potential weakens the negative surface potential,but its local weak binding to the isopropyl group facilitates hydrophobic interaction between Aβ42 and L-NIBC and resultedfiber aggregate.Conversely,electrostatic interaction between Aβ42 and D-NIBC induces spherical oligomer.Thesefindings provide new insight into molecular nature of chirality-regulated biological effect.展开更多
The aggregation ofα-synuclein(α-syn)is strongly influenced by membrane interfaces,but the mechanism of transition from monomers to oligomers at early aggregation stage is not clear.Here,we investigate the adsorption...The aggregation ofα-synuclein(α-syn)is strongly influenced by membrane interfaces,but the mechanism of transition from monomers to oligomers at early aggregation stage is not clear.Here,we investigate the adsorption and structure changes ofα-syn on oppositely charged aromatic interfaces through in-situ surface-enhanced infrared absorption(SEIRA)spectroscopy and nano-IR technique.The results show that the synergy of electrostatic and hydrophobic interactions leads to a“fast-slow”two-step aggregation pathway on negatively charged interface.Surface adsorption induces the formation of an extended helix structure and subsequently partial helix unwinding in NAC region,which enables the hydrophobic stacking between nearby NAC regions.Stable antiparallel β-sheet rich aggregates are gradually emerging as further interactions of monomers with the fast formed“first layer”.Monomers electrostatically adsorb on positively charged interface by C-terminus with NAC region and N-terminus stretched in solvent,which serve as an aggregation core and induce further adsorption and gradual formation of aggregates with C-terminus exposure.Our results demonstrate the modulation of surface charge and synergy of electrostatic and hydrophobic interactions on the interaction modes and aggregation pathways,which provide insights into dynamic conformation changes ofα-syn at early aggregation stage and imply the important role of spatial-temporal heterogeneity of membranes inα-synucleinopathies.展开更多
Comprehensive Summary,The worldwide abuse of antibiotics and resultant antimicrobial resistance made the development of new antibacterial materials an urgent and significant issue.Herein,a hybrid ZnO@Au nanorod array ...Comprehensive Summary,The worldwide abuse of antibiotics and resultant antimicrobial resistance made the development of new antibacterial materials an urgent and significant issue.Herein,a hybrid ZnO@Au nanorod array with fast bacterial inactivation and excellent recyclability was reported.93%bacteria could be inactivated within 5 min ultra-sonication under indoor daylight,and the killing rate maintains above 90%after seven repeated using cycles.Antibacterial mechanism involves extracellular reactive oxygen species(ROS)generated from photocatalysis and piezoelectricity of nanorod array,intracellular ROS generation and decrease of adenosine-triphosphate(ATP)originated from electron transfer(ET)from bacteria to nanorod array,as well as mechanical effect from the nanorod,among which ET mechanism plays a major role.Large Schottky barrier from the hybrid interface not only enhances the ROS generation by promoting the charge transfer and carrier separation as well as light utilization,but also enables one-direction electron transfer from bacteria to nanorod array.The resultant continuous electron loss breaks the energy metabolism and disturbs the redox equilibrium,leading to bacterial death.This study demonstrates the great potential of hybrid structure in antibacterial applications and indicates ET as a novel effective antibacterial mechanism for semiconductor materials,which provides insights into the design of next-generation antibacterial materials.展开更多
Novel nitrogen doped carbon quantum dots were successfully fabricated by a hydrothermal method wxth eggplam sepals as carbon source. The carbon materials were characterized by transmission electron microscopy （TEM）,...Novel nitrogen doped carbon quantum dots were successfully fabricated by a hydrothermal method wxth eggplam sepals as carbon source. The carbon materials were characterized by transmission electron microscopy （TEM）, UV-Vis adsorption, Fourier-transformed infrared spectroscopy （FTIR）, fluorescence and the X-ray photoelectron spectroscopy （XPS） measurements, respectively. The carbon quantum dots showed excellent photoluminescence property with high stability in phosphate buffer solution with different pH values from 5 to 9, even in the cell culture medium supplied with the fetal bovine serum. Meanwhile, we also studied the interaction of carbon quantum dots with living HeLa cells with confocal microscopy. Our results indicated that the carbon quantum dots can enter the living HeLa cells by cellular penetration.展开更多
Ferroptosis is a cell death pathway mediated by iron-dependent accumulation of lipid peroxide.However,the specific downstream molecular events of iron-dependent lipid peroxidation are yet to be elucidated.In this stud...Ferroptosis is a cell death pathway mediated by iron-dependent accumulation of lipid peroxide.However,the specific downstream molecular events of iron-dependent lipid peroxidation are yet to be elucidated.In this study,based on various spectral analyses,we have found evidence that singlet oxygen is produced through the Russell mechanism during the self-reaction of lipid peroxyl radicals generated via iron-dependent lipid peroxidation regardless of the presence of cholesterol.Significantly reduced generation of singlet oxygen was observed in the absence of iron.The generated singlet oxygen accelerated the oxidative damage of lipid membranes by propagating lipid peroxidation and facilitated ferroptotic cancer cell death initiated by erastin.In this work,singlet oxygen has been revealed to be a new reactive species that participates in ferroptosis,thus improving the understanding on iron-dependent lipid peroxidation and the mechanism of ferroptosis.展开更多
基金National Key R&D Program of China,Grant/Award Number:2022YFE0113000National Science Fund for Distinguished Young Scholars,Grant/Award Number:22025406。
文摘Surface chirality plays an important role in determining the biological effect,but the molecular nature beyond stereoselectivity is still unknown.Herein,through surface-enhanced infrared absorption spectroscopy,electrochemistry,and theoretical simulations,we found diasteromeric monolayers induced by assembled density on chiral gold nanofilm and identified the positive contribution of water dipole poten-tial at chiral interface and their different interfacial interactions,which result in a difference both in the positive dipoles of interfacial water compensating the negative surface potential of the SAM and in the hindrance effect of interface dehydration,thereby regulating the interaction between amyloid-βpeptide(Aβ)and N-isobutyryl-cysteine(NIBC).Water on L-NIBC interface which shows stronger positive dipole potential weakens the negative surface potential,but its local weak binding to the isopropyl group facilitates hydrophobic interaction between Aβ42 and L-NIBC and resultedfiber aggregate.Conversely,electrostatic interaction between Aβ42 and D-NIBC induces spherical oligomer.Thesefindings provide new insight into molecular nature of chirality-regulated biological effect.
基金financial support from National Key R&D Program of China(2022YFE0113000)the National Natural Science Foundation of China(22074138,22374083)+1 种基金the National Science Fund for Distinguished Young Scholars(22025406)Youth Innovation Promotion Association of CAs(Grant No.2020233).
文摘The aggregation ofα-synuclein(α-syn)is strongly influenced by membrane interfaces,but the mechanism of transition from monomers to oligomers at early aggregation stage is not clear.Here,we investigate the adsorption and structure changes ofα-syn on oppositely charged aromatic interfaces through in-situ surface-enhanced infrared absorption(SEIRA)spectroscopy and nano-IR technique.The results show that the synergy of electrostatic and hydrophobic interactions leads to a“fast-slow”two-step aggregation pathway on negatively charged interface.Surface adsorption induces the formation of an extended helix structure and subsequently partial helix unwinding in NAC region,which enables the hydrophobic stacking between nearby NAC regions.Stable antiparallel β-sheet rich aggregates are gradually emerging as further interactions of monomers with the fast formed“first layer”.Monomers electrostatically adsorb on positively charged interface by C-terminus with NAC region and N-terminus stretched in solvent,which serve as an aggregation core and induce further adsorption and gradual formation of aggregates with C-terminus exposure.Our results demonstrate the modulation of surface charge and synergy of electrostatic and hydrophobic interactions on the interaction modes and aggregation pathways,which provide insights into dynamic conformation changes ofα-syn at early aggregation stage and imply the important role of spatial-temporal heterogeneity of membranes inα-synucleinopathies.
基金supported by the Youth Innovation Promotion Association of CAS(Grant No.2020233)the National Natural Science Foundation of China(22074138)+2 种基金the National Science Fund for Distinguished Young Scholars(22025406)the Science and Technology Innovation Foundation of Jjilin Province(YDZJ202101ZYTS039,20220101065JC)Liaoning Provincial Department of Education Fund(UJKMz20220790).
文摘Comprehensive Summary,The worldwide abuse of antibiotics and resultant antimicrobial resistance made the development of new antibacterial materials an urgent and significant issue.Herein,a hybrid ZnO@Au nanorod array with fast bacterial inactivation and excellent recyclability was reported.93%bacteria could be inactivated within 5 min ultra-sonication under indoor daylight,and the killing rate maintains above 90%after seven repeated using cycles.Antibacterial mechanism involves extracellular reactive oxygen species(ROS)generated from photocatalysis and piezoelectricity of nanorod array,intracellular ROS generation and decrease of adenosine-triphosphate(ATP)originated from electron transfer(ET)from bacteria to nanorod array,as well as mechanical effect from the nanorod,among which ET mechanism plays a major role.Large Schottky barrier from the hybrid interface not only enhances the ROS generation by promoting the charge transfer and carrier separation as well as light utilization,but also enables one-direction electron transfer from bacteria to nanorod array.The resultant continuous electron loss breaks the energy metabolism and disturbs the redox equilibrium,leading to bacterial death.This study demonstrates the great potential of hybrid structure in antibacterial applications and indicates ET as a novel effective antibacterial mechanism for semiconductor materials,which provides insights into the design of next-generation antibacterial materials.
基金supported by the National Science Foundation for Excellent Young Scholar of China(21322510)the Natural Science Foundation of Jilin Province(201215092)the President Funds of the Chinese Academy of Sciences
文摘Novel nitrogen doped carbon quantum dots were successfully fabricated by a hydrothermal method wxth eggplam sepals as carbon source. The carbon materials were characterized by transmission electron microscopy （TEM）, UV-Vis adsorption, Fourier-transformed infrared spectroscopy （FTIR）, fluorescence and the X-ray photoelectron spectroscopy （XPS） measurements, respectively. The carbon quantum dots showed excellent photoluminescence property with high stability in phosphate buffer solution with different pH values from 5 to 9, even in the cell culture medium supplied with the fetal bovine serum. Meanwhile, we also studied the interaction of carbon quantum dots with living HeLa cells with confocal microscopy. Our results indicated that the carbon quantum dots can enter the living HeLa cells by cellular penetration.
基金the National Science Fund for Distinguished Young Scholars(Grant No.22025406)the National Natural Science Foundation of China(Grants No.21874125,22074138)+1 种基金Science and Technology Innovation Foundation of Jilin Province(Grants No.20190201074JC,20200703021ZP)the Youth Innovation Promotion Association of CAS(Grant No.2020233).
文摘Ferroptosis is a cell death pathway mediated by iron-dependent accumulation of lipid peroxide.However,the specific downstream molecular events of iron-dependent lipid peroxidation are yet to be elucidated.In this study,based on various spectral analyses,we have found evidence that singlet oxygen is produced through the Russell mechanism during the self-reaction of lipid peroxyl radicals generated via iron-dependent lipid peroxidation regardless of the presence of cholesterol.Significantly reduced generation of singlet oxygen was observed in the absence of iron.The generated singlet oxygen accelerated the oxidative damage of lipid membranes by propagating lipid peroxidation and facilitated ferroptotic cancer cell death initiated by erastin.In this work,singlet oxygen has been revealed to be a new reactive species that participates in ferroptosis,thus improving the understanding on iron-dependent lipid peroxidation and the mechanism of ferroptosis.
