Metal–organic frameworks(MOFs)have attracted significant research interest in biomimetic catalysis.However,the modulation of the activity of MOFs by precisely tuning the coordination of metal nodes is still a signifi...Metal–organic frameworks(MOFs)have attracted significant research interest in biomimetic catalysis.However,the modulation of the activity of MOFs by precisely tuning the coordination of metal nodes is still a significant challenge.Inspired by metalloenzymes with well-defined coordination structures,a series of MOFs containing halogen-coordinated copper nodes(Cu-X MOFs,X=Cl,Br,I)are employed to elucidate their structure–activity relationship.Intriguingly,experimental and theoretical results strongly support that precisely tuning the coordination of halogen atoms directly regulates the enzyme-like activities of Cu-X MOFs by influencing the spatial configuration and electronic structure of the Cu active center.The optimal Cu–Cl MOF exhibits excellent superoxide dismutase-like activity with a specific activity one order of magnitude higher than the reported Cu-based nanozymes.More importantly,by performing enzyme-mimicking catalysis,the Cu–Cl MOF nanozyme can significantly scavenge reactive oxygen species and alleviate oxidative stress,thus effectively relieving ocular chemical burns.Mechanistically,the antioxidant and antiapoptotic properties of Cu–Cl MOF are achieved by regulating the NRF2 and JNK or P38 MAPK pathways.Our work provides a novel way to refine MOF nanozymes by directly engineering the coordination microenvironment and,more significantly,demonstrating their potential therapeutic effect in ophthalmic disease.展开更多
Flexible biosensors with high accuracy and reliable operation in detecting pH and uric acid levels in body fluids are fabricated using well-engineered metaldoped porous carbon as electrode material.The gold nanopartic...Flexible biosensors with high accuracy and reliable operation in detecting pH and uric acid levels in body fluids are fabricated using well-engineered metaldoped porous carbon as electrode material.The gold nanoparticles@N-doped carbon in situ are prepared using wool keratin as both a novel carbon precursor and a stabilizer.The conducting electrode material is fabricated at 500℃ under customized parameters,which mimics A-B type(two different repeating units) polymeric material and displays excellent deprotonation performance(pH sensitivity).The obtained pH sensor exhibits high pH sensitivity of 57 mV/pH unit and insignificant relative standard deviation of 0.088%.Conversely,the composite carbon material with sp^2 structure prepared at 700℃ is doped with nitrogen and gold nanoparticles,which exhibits good conductivity and electrocatalytic activity for uric acid oxidation.The uric acid sensor has linear response over a range of 1-150 μM and a limit of detection 0.1 μM.These results will provide new avenues where biological material will be the best start,which can be useful to target contradictory applications through molecular engineering at mesoscale.展开更多
Several p H-dependent processes and reactions take place in the human body;hence,the p H of body fluids is the best indicator of disturbed health conditions.However,accurate and real-time diagnosis of the p H of body ...Several p H-dependent processes and reactions take place in the human body;hence,the p H of body fluids is the best indicator of disturbed health conditions.However,accurate and real-time diagnosis of the p H of body fluids is complicated because of limited commercially available p H sensors.Hence,we aimed to prepare a flexible,transparent,disposable,userfriendly,and economic strip-based solid-state p H sensor using palladium nanoparticles(Pd NPs)/N-doped carbon(NC)composite material.The Pd NPs/NC composite material was synthesized using wool keratin(WK)as a precursor.The insitu prepared Pd NPs played a key role in the controlled switching of protein structure to the N-doped carbon skeleton withπ–πarrangement at the mesoscale level,which mimics the A–B type polymeric structure,and hence,is highly susceptible to H+ions.The optimized carbonization condition in the presence of Pd NPs showed that the material obtained using a modified Ag/Ag Cl reference electrode had the highest p H sensitivity with excellent stability and durability.The optimized p H sensor showed high specificity and selectivity with a sensitivity of 55 m V/p H unit and a relative standard deviation of 0.79%.This study is the first to synthesize Pd NPs using WK as a stabilizing and reducing agent.The applicability of the sensor was investigated for biological samples,namely,saliva and gastric juices.The proposed protocol and material have implications in solid-state chemistry,where biological material will be the best choice for the synthesis of materials with anticipated performance.展开更多
It is well-established that high carbonization temperature will trigger the enzyme-like activity of carbon-based materials.However,the catalytic mechanism is still ambiguous,which hinders the further rational design o...It is well-established that high carbonization temperature will trigger the enzyme-like activity of carbon-based materials.However,the catalytic mechanism is still ambiguous,which hinders the further rational design of nanomaterials as enzyme mimics.Hereby,N,S-rich carbonized wool nanosheets(CWs)were synthesized at different pyrolysis temperatures.As expected,only CWs treated with high-temperature possess intrinsic oxidase-and peroxidase-like activities.Meanwhile,density functional theory(DFT)calculations demonstrate that graphitic nitrogen and the co-existence of nitrogen and sulfur in the carbon matrix serve as the active sites for the enzyme-like process.More importantly,combining theoretical calculations and experimental observations,the high-temperature triggered catalytic mechanism can be ascribed to the fact that an appropriate high-temperature maximizes the graphitization degree to a certain extent,at which most of the catalytic active sites are well retained rather than evaporating.Moreover,coupling with excellent photothermal conversion efficiency and catalytic performance,CWs can be applied to photothermal-catalytic cancer therapy under near-infrared region(NIR)light irradiation.We believe this work will contribute to understanding the catalytic mechanism of carbon-based nanozymes and promote the development of new biomedical and pharmaceutical applications.展开更多
Functional carbon nanomaterials have become the stars of many active research fields,such as electronics,energy,catalysis,imaging,sensing and biomedicine.Herein,a facile and one-pot strategy for generating ferromagnet...Functional carbon nanomaterials have become the stars of many active research fields,such as electronics,energy,catalysis,imaging,sensing and biomedicine.Herein,a facile and one-pot strategy for generating ferromagnetic nanoparticles loaded on N-doped carbon nanosheets(Fe-N-CNS)is presented by salt-assisted high-temperature carbonization of natural silk proteins.Due to their graphitic structures,N-doping and ferromagnetic nanoparticles(FeN_(x),FeO_(y),FeC_(z)),the silk-derived Fe-N-CNS can act as excellent mimics of both peroxidase and oxidase.Benefiting from the combined character of the graphene-like structures and enzyme-like activities,Fe-N-CNS can be further applied to highly efficient dye removal via synergistic adsorption and degradation.Meanwhile,the as-prepared Fe-N-CNS with intrinsic magnetism and electrical conductivity can also serve as an efficient electromagnetic wave absorption agent.The broadest effective absorption bandwidth(EAB)of as-obtained absorbing material yields a 6.73 GHz with 1 mm thickness,with a maximum reflection loss of-37.33 dB(11.41 GHz).The EAB can cover2~18 GHz with a tunable absorber thickness from 1.0 mm to 5.0 mm.Collectively,Fe-N-CNS,as a dualfunctional material,can tackle the aggravating environmental pollution issues of both dyes and electromagnetic waves.展开更多
Nanozymes are nanomaterials with enzymatic properties that address the shortcomings of natural enzymes.Among them,many nanozymes could absorb near-infrared(NIR)light and respond to NIR light stimulation,providing us w...Nanozymes are nanomaterials with enzymatic properties that address the shortcomings of natural enzymes.Among them,many nanozymes could absorb near-infrared(NIR)light and respond to NIR light stimulation,providing us with a new perspective to regulate their catalytic performance.During the past several years,the use of NIR light as an external stimulus has made considerable progress,which has given a powerful shove-ahead to their applications in biomedical fields.This review highlights recent advances in the application of NIR light-responsive nanozyme-based systems.First,we will discuss the mechanisms of such NIR light-regulated nanozymes.Then,various strategies are summarized to construct effective NIR light-responsive nanozymes.After that,this remote-controlled catalytic system covers multiple applications,from bactericidal to tumor therapeutics.Finally,the challenges faced by NIR light-responsive nanozymes are outlined and future directions for advancing NIR light-responsive nanozyme research are proposed.We anticipate that this review will guide and inspire researchers to synthesize effective NIR-activated nanozymes and may promote breakthroughs in this field.展开更多
Design and development of iron porphyrin-based artificial enzymes system have been attracting a lot of attention.Herein,without any toxic reductant and harsh processing,we present a facile one-pot method to fabricate ...Design and development of iron porphyrin-based artificial enzymes system have been attracting a lot of attention.Herein,without any toxic reductant and harsh processing,we present a facile one-pot method to fabricate bifunctional catalytic nanocomposites consisting of graphene and hemin by using vitamin C as a mild reduction reagent.The presence of graphene helps the formation of a high degree of highly active and stable hemin on the graphene surface in a monomeric form through theirπ-πstacking interaction.As a result,such nanocomposites possess a superior adsorption capacity and intrinsic peroxidase-like catalytic activity.Moreover,by the combination of their dye adsorption ability,RGOhemin nanocomposites can serve as a suitable candidate for efficient capture and removal of dyes via a synergistic effect.Our findings may pave the way to apply graphene-supported artificial enzymes in a variety of fields,such as environmental chemistry,bionics,medicine,and biotechnology.展开更多
基金the National Key R&D Program of China(Grant No.2020YFA0908100)the National Nature Science Foundation(Grant Nos.12274356,82070931,and 82271045)+1 种基金Fundamental Research Funds for the Central Universities(20720220022)the 111 Project(B16029)。
文摘Metal–organic frameworks(MOFs)have attracted significant research interest in biomimetic catalysis.However,the modulation of the activity of MOFs by precisely tuning the coordination of metal nodes is still a significant challenge.Inspired by metalloenzymes with well-defined coordination structures,a series of MOFs containing halogen-coordinated copper nodes(Cu-X MOFs,X=Cl,Br,I)are employed to elucidate their structure–activity relationship.Intriguingly,experimental and theoretical results strongly support that precisely tuning the coordination of halogen atoms directly regulates the enzyme-like activities of Cu-X MOFs by influencing the spatial configuration and electronic structure of the Cu active center.The optimal Cu–Cl MOF exhibits excellent superoxide dismutase-like activity with a specific activity one order of magnitude higher than the reported Cu-based nanozymes.More importantly,by performing enzyme-mimicking catalysis,the Cu–Cl MOF nanozyme can significantly scavenge reactive oxygen species and alleviate oxidative stress,thus effectively relieving ocular chemical burns.Mechanistically,the antioxidant and antiapoptotic properties of Cu–Cl MOF are achieved by regulating the NRF2 and JNK or P38 MAPK pathways.Our work provides a novel way to refine MOF nanozymes by directly engineering the coordination microenvironment and,more significantly,demonstrating their potential therapeutic effect in ophthalmic disease.
基金supported by the National Natural Science Foundation of China(Grant Nos.51502253,U1405226,21503175,51773171,and 21705135)Natural Science Foundation of Guangdong Province(Grant No.2016A030310369)+5 种基金Natural Science Foundation of Fujian Province(Grant No.2017J01104)the Fundamental Research Funds for the Central Universities of China(Grant Nos.20720160127 and 20720180013)Doctoral Fund of the Ministry of Education(Grant No.20130121110018)NUS Ac RF Tier 1(Grant No.R-144-000-367-112)the “111” Project(Grant No.B16029)the 1000 Talents Program funding from the Xiamen University。
文摘Flexible biosensors with high accuracy and reliable operation in detecting pH and uric acid levels in body fluids are fabricated using well-engineered metaldoped porous carbon as electrode material.The gold nanoparticles@N-doped carbon in situ are prepared using wool keratin as both a novel carbon precursor and a stabilizer.The conducting electrode material is fabricated at 500℃ under customized parameters,which mimics A-B type(two different repeating units) polymeric material and displays excellent deprotonation performance(pH sensitivity).The obtained pH sensor exhibits high pH sensitivity of 57 mV/pH unit and insignificant relative standard deviation of 0.088%.Conversely,the composite carbon material with sp^2 structure prepared at 700℃ is doped with nitrogen and gold nanoparticles,which exhibits good conductivity and electrocatalytic activity for uric acid oxidation.The uric acid sensor has linear response over a range of 1-150 μM and a limit of detection 0.1 μM.These results will provide new avenues where biological material will be the best start,which can be useful to target contradictory applications through molecular engineering at mesoscale.
基金supported by the National Natural Science Foundation of China(Grant Nos.51502253,U1405226,21503175,and 21705135)Natural Science Foundation of Guangdong Province,China(Grant No.2016A030310369)Natural Science Foundation of Fujian Province,China(Grant No.2017J01104)。
文摘Several p H-dependent processes and reactions take place in the human body;hence,the p H of body fluids is the best indicator of disturbed health conditions.However,accurate and real-time diagnosis of the p H of body fluids is complicated because of limited commercially available p H sensors.Hence,we aimed to prepare a flexible,transparent,disposable,userfriendly,and economic strip-based solid-state p H sensor using palladium nanoparticles(Pd NPs)/N-doped carbon(NC)composite material.The Pd NPs/NC composite material was synthesized using wool keratin(WK)as a precursor.The insitu prepared Pd NPs played a key role in the controlled switching of protein structure to the N-doped carbon skeleton withπ–πarrangement at the mesoscale level,which mimics the A–B type polymeric structure,and hence,is highly susceptible to H+ions.The optimized carbonization condition in the presence of Pd NPs showed that the material obtained using a modified Ag/Ag Cl reference electrode had the highest p H sensitivity with excellent stability and durability.The optimized p H sensor showed high specificity and selectivity with a sensitivity of 55 m V/p H unit and a relative standard deviation of 0.79%.This study is the first to synthesize Pd NPs using WK as a stabilizing and reducing agent.The applicability of the sensor was investigated for biological samples,namely,saliva and gastric juices.The proposed protocol and material have implications in solid-state chemistry,where biological material will be the best choice for the synthesis of materials with anticipated performance.
基金funded by the National Natural Science Foundation of China(Nos.12274356,22275081)Key Laboratory of Pharmaceutical Analysis and Laboratory Medicine(Putian University)(No.PALM 202206)+1 种基金Fujian Province University,the Fundamental Research Funds for the Central Universities(No.20720220022)the 111 Project(No.B16029)。
文摘It is well-established that high carbonization temperature will trigger the enzyme-like activity of carbon-based materials.However,the catalytic mechanism is still ambiguous,which hinders the further rational design of nanomaterials as enzyme mimics.Hereby,N,S-rich carbonized wool nanosheets(CWs)were synthesized at different pyrolysis temperatures.As expected,only CWs treated with high-temperature possess intrinsic oxidase-and peroxidase-like activities.Meanwhile,density functional theory(DFT)calculations demonstrate that graphitic nitrogen and the co-existence of nitrogen and sulfur in the carbon matrix serve as the active sites for the enzyme-like process.More importantly,combining theoretical calculations and experimental observations,the high-temperature triggered catalytic mechanism can be ascribed to the fact that an appropriate high-temperature maximizes the graphitization degree to a certain extent,at which most of the catalytic active sites are well retained rather than evaporating.Moreover,coupling with excellent photothermal conversion efficiency and catalytic performance,CWs can be applied to photothermal-catalytic cancer therapy under near-infrared region(NIR)light irradiation.We believe this work will contribute to understanding the catalytic mechanism of carbon-based nanozymes and promote the development of new biomedical and pharmaceutical applications.
基金funded by the National Nature Science Foundation(Nos.21901110,52001265 and 12274356)Natural Science Foundation of Fujian Province(No.2021J01847)+3 种基金Fujian Provincial Department of Education Fund(No.JAT190337)Fujian Provincial Department of Science and Technology(No.2019J06001)the Open Fund of Xiamen Key Laboratory of Marine Corrosion and Smart Protective Materialsthe 111 Project(No.B16029)。
文摘Functional carbon nanomaterials have become the stars of many active research fields,such as electronics,energy,catalysis,imaging,sensing and biomedicine.Herein,a facile and one-pot strategy for generating ferromagnetic nanoparticles loaded on N-doped carbon nanosheets(Fe-N-CNS)is presented by salt-assisted high-temperature carbonization of natural silk proteins.Due to their graphitic structures,N-doping and ferromagnetic nanoparticles(FeN_(x),FeO_(y),FeC_(z)),the silk-derived Fe-N-CNS can act as excellent mimics of both peroxidase and oxidase.Benefiting from the combined character of the graphene-like structures and enzyme-like activities,Fe-N-CNS can be further applied to highly efficient dye removal via synergistic adsorption and degradation.Meanwhile,the as-prepared Fe-N-CNS with intrinsic magnetism and electrical conductivity can also serve as an efficient electromagnetic wave absorption agent.The broadest effective absorption bandwidth(EAB)of as-obtained absorbing material yields a 6.73 GHz with 1 mm thickness,with a maximum reflection loss of-37.33 dB(11.41 GHz).The EAB can cover2~18 GHz with a tunable absorber thickness from 1.0 mm to 5.0 mm.Collectively,Fe-N-CNS,as a dualfunctional material,can tackle the aggravating environmental pollution issues of both dyes and electromagnetic waves.
基金funded by the National Natural Science Foundation of China(12274356)the Fundamental Research Funds for the Central Universities(20720220022)the 111 Project(B16029)
文摘Nanozymes are nanomaterials with enzymatic properties that address the shortcomings of natural enzymes.Among them,many nanozymes could absorb near-infrared(NIR)light and respond to NIR light stimulation,providing us with a new perspective to regulate their catalytic performance.During the past several years,the use of NIR light as an external stimulus has made considerable progress,which has given a powerful shove-ahead to their applications in biomedical fields.This review highlights recent advances in the application of NIR light-responsive nanozyme-based systems.First,we will discuss the mechanisms of such NIR light-regulated nanozymes.Then,various strategies are summarized to construct effective NIR light-responsive nanozymes.After that,this remote-controlled catalytic system covers multiple applications,from bactericidal to tumor therapeutics.Finally,the challenges faced by NIR light-responsive nanozymes are outlined and future directions for advancing NIR light-responsive nanozyme research are proposed.We anticipate that this review will guide and inspire researchers to synthesize effective NIR-activated nanozymes and may promote breakthroughs in this field.
基金supported by the National Nature Science Foundation (Nos.21771150,21401154,U1405226)the Fundamental Research Funds for the Central Universities of China (Nos. 20720170011,20720140528,20720160127)+1 种基金111 Project (No. B16029)Doctoral Fund of the Ministry of Education (No.20130121110018)
文摘Design and development of iron porphyrin-based artificial enzymes system have been attracting a lot of attention.Herein,without any toxic reductant and harsh processing,we present a facile one-pot method to fabricate bifunctional catalytic nanocomposites consisting of graphene and hemin by using vitamin C as a mild reduction reagent.The presence of graphene helps the formation of a high degree of highly active and stable hemin on the graphene surface in a monomeric form through theirπ-πstacking interaction.As a result,such nanocomposites possess a superior adsorption capacity and intrinsic peroxidase-like catalytic activity.Moreover,by the combination of their dye adsorption ability,RGOhemin nanocomposites can serve as a suitable candidate for efficient capture and removal of dyes via a synergistic effect.Our findings may pave the way to apply graphene-supported artificial enzymes in a variety of fields,such as environmental chemistry,bionics,medicine,and biotechnology.
