During criminal case investigations,blood evidence tracing is critical for criminal investigation.However,the blood stains are often cleaned or covered up after the crime,resulting in trace residue and difficult track...During criminal case investigations,blood evidence tracing is critical for criminal investigation.However,the blood stains are often cleaned or covered up after the crime,resulting in trace residue and difficult tracking.Therefore,a highly sensitive and specific method for the rapid detection of human blood stains remains urgent.To solve this problem,we established a nanozyme-based strip for rapid detection of blood evidence with high sensitivity and specificity.To construct reliable nanozyme strips,we synthesized CoFe_(2)O_(4) nanozymes with high peroxidase-like activity by scaling up to gram level,which can be supplied for six million tests,and conjugated antibody as a detection probe in nanozyme strip.The developed CoFe_(2)O_(4) nanozyme strip can detect human hemoglobin(HGB)at a concentration as low as 1 ng/mL,which is 100 times lower than the commercially available colloidal gold strips(100 ng/mL).Moreover,this CoFe_(2)O_(4) nanozyme strip showed high generality on 12 substrates and high specificity to human HGB among 13 animal blood samples.Finally,we applied the developed CoFe_(2)O_(4) nanozyme strip to successfully detect blood stains in three real cases,where the current commercial colloidal gold strip failed to do.The results suggest that the CoFe_(2)O_(4) nanozyme strip can be used as an effective on-scene detection method for human blood stains,and can further be used as a long-term preserved material evidence for traceability inquiry.展开更多
Although nanozymes have been widely developed,accurate design of highly active sites at the atomic level to mimic the electronic and geometrical structure of enzymes and the exploration of underlying mechanisms still ...Although nanozymes have been widely developed,accurate design of highly active sites at the atomic level to mimic the electronic and geometrical structure of enzymes and the exploration of underlying mechanisms still face significant challenges.Herein,two functional groups with opposite electron modulation abilities(nitro and amino)were introduced into the metal–organic frameworks(MIL-101(Fe))to tune the atomically dispersed metal sites and thus regulate the enzymelike activity.Notably,the functionalization of nitro can enhance the peroxidase(POD)-like activity of MIL-101(Fe),while the amino is poles apart.Theoretical calculations demonstrate that the introduction of nitro can not only regulate the geometry of adsorbed intermediates but also improve the electronic structure of metal active sites.Benefiting from both geometric and electronic effects,the nitro-functionalized MIL-101(Fe)with a low reaction energy barrier for the HO*formation exhibits a superior POD-like activity.As a concept of the application,a nitro-functionalized MIL-101(Fe)-based biosensor was elaborately applied for the sensitive detection of acetylcholinesterase activity in the range of 0.2–50 mU mL−1 with a limit of detection of 0.14 mU mL−1.Moreover,the detection of organophosphorus pesticides was also achieved.This work not only opens up new prospects for the rational design of highly active nanozymes at the atomic scale but also enhances the performance of nanozyme-based biosensors.展开更多
A new ratiometric fluorescent sensor based on the bifunctional carbon quantum dots(CQDs)@metal-organic framework(MOF)nanocomposite possessing peroxidase-mimicking catalytic and luminescent characteristics was develope...A new ratiometric fluorescent sensor based on the bifunctional carbon quantum dots(CQDs)@metal-organic framework(MOF)nanocomposite possessing peroxidase-mimicking catalytic and luminescent characteristics was developed for hydrogen peroxide(H_(2)O_(2))and cholesterol detection.The incorporation of fluorescent CQDs into the cavities of MIL-101(Fe)MOF with peroxidase-like activities endows the nanocomposite with bifunctional properties.The CQDs@MOF can oxidize o-phenylene-diamine to 2,3-diaminophenolazine by H_(2)O_(2)with yellow fluorescence(556 nm).Meantime,the intrinsic fluorescence signal(455 nm)of CQDs@MOF is inhibited due to the inner filter effect.Therefore,the ratio of the fluorescent intensity is employed as the signal output to construct the H_(2)O_(2)ratiometric biosensor.In addition,the cholesterol can be determined by the ratiometric sensor with high sensitivity.In addition,the total cholesterol in human serum is determined with high accuracy using our ratiometric biosensor.This ratiometric fluorescent platform based on the bifunctional CQDs@MOF provides new insights in the field of bio-sensing.展开更多
Nanozyme antibacterial agents with high enzyme-like catalytic activity and strong bacteria-binding ability have provided an alternative method to efficiently disinfect drug-resistance microorganism.Herein,the carbon n...Nanozyme antibacterial agents with high enzyme-like catalytic activity and strong bacteria-binding ability have provided an alternative method to efficiently disinfect drug-resistance microorganism.Herein,the carbon nitride quantum dots(CNQDs)nanozymes with high nitrogen vacancies(NVs)were mass-productively prepared by a simple ultrasonic-crushing method assisted by propylene glycol.It was found that the NVs of CNQDs were stemmed from the selective breaking of surface N-(C)_(2)sites,accounting for 6.2%.Experiments and density functional theory(DFT)simulations have demonstrated that the presence of NVs can alter the local electron distribution and extend theπ-electron delocalization to enhance the peroxidase-like activity.Biocompatible CNQDs could enter inside microorganisms by diffusion and elevate the bacteria-binding ability,which enhanced the accurate and rapid attack of·OH to the microorganisms.The sterilization rate of CNQDs against Gram-negative bacteria(E.coli),Gram-positive bacteria(S.aureus,B.subtilis),fungi(R.solani)reaches more than 99%.Thus,this work showed great potential for engineered nanozymes for broad-spectrum antibacterial in biomedicine and environmental protection.展开更多
Artificial enzymes have provided great antimicrobial activity to combat wound infection.However,the lack of tissue repair capability compromised their treatment effect.Therefore,development of novel artificial enzyme ...Artificial enzymes have provided great antimicrobial activity to combat wound infection.However,the lack of tissue repair capability compromised their treatment effect.Therefore,development of novel artificial enzyme concurrently with the excellent antibacterial activity and the property of promoting wound healing are required.Here,we demonstrated the hydrogel-based artificial enzyme composed of copper and amino acids possessed intrinsic peroxidase-like catalytic activity,which could combat wound pathogen effectively and accelerate wound healing by stimulating angiogenesis and collagen deposition.Furthermore,the system possesses good biocompatibility for practical application.The synergic effect of the hydrogel-based artificial enzyme promises the system as a new paradigm in bacteria-infected wound healing therapy.展开更多
The controllable growth of metal nanoparticles on nanomaterials is becoming an effective strategy for developing nanocomposites with designated performance.Herein,a simple and mild strategy for the in situ growth of P...The controllable growth of metal nanoparticles on nanomaterials is becoming an effective strategy for developing nanocomposites with designated performance.Herein,a simple and mild strategy for the in situ growth of Pt–Pd bimetallic nanoparticles on covalent organic frameworks(COFs)to regulate the nanozyme activity was designed for colorimetric detection of hydrogen peroxide(H2O2)and glutathione(GSH).The COFs not only offer sufficient loading sites for the uniform dispersion of Pt–Pd bimetallic nanoparticles,but also increase the adsorption of substrate to promote the catalytic reaction.With the bimetallic synergistic effect of Pt–Pd nanoparticles,the prepared multifunctional nanozyme(Pt–Pd/COFs nanozyme)simultaneously exhibited superior peroxidase(POD)-like activity and oxidase(OXD)-like activity.Using the multifunctional nanozyme,a colorimetric sensing system was constructed for sensitive detection of H2O2 and GSH,with the wide linear ranges of 5–1000µmol/L and 1–40µmol/L,and the detection limits were 1.14μmol/L and 0.43μmol/L,respectively.It was successfully used for the detection of real samples in environmental water and serum,providing a simple method for disease diagnosis and environmental monitoring.展开更多
Carbon-based single-atom catalysts(SACs)have been widely studied in the field of biomedicine due to their excellent catalytic performance.However,carbon-based SACs usually aggregate during pyrolysis,which leads to the...Carbon-based single-atom catalysts(SACs)have been widely studied in the field of biomedicine due to their excellent catalytic performance.However,carbon-based SACs usually aggregate during pyrolysis,which leads to the reduction of catalytic activity.Here,we describe a method to improve the monodispersion of SACs using silicon dioxide as a protective layer.The decoration of silicon dioxide serves as a buffer layer for individual nanoparticles,which is not destroyed during the pyrolysis process,ensuring the single-particle dispersion of the nanoparticles after etching.This approach increased the hydroxyl groups on the surface of Fe-SAC(Fe-SAC-SE)and improved its water solubility,resulting in a four times enhancement of the peroxidase(POD)-like activity of Fe-SAC-SE(58.4 U/mg)than that of non-protected SACs(13.9 U/mg).The SiO_(2)-protection approach could also improve the catalytic activities of SACs with other metals such as Mn,Co,Ni,and Cu,indicating its generality for SACs preparation.Taking advantage of the high POD-like activity,photothermal properties,and large specific surface area of Fe-SAC-SE,we constructed a synergistic therapeutic system(Fe-SAC-SE@DOX@PEG)for combining the photothermal therapy,catalytic therapy,and chemotherapy.It was verified that the photothermal properties of Fe-SAC-SE@DOX@PEG could effectively improve its POD-like activity,exhibiting excellent tumor-killing performance at the cellular level.This work may provide a general approach to improve the performances of SACs for disease therapy and diagnosis.展开更多
Bacterial pathogens pose a serious threat to human health,and there is an urgent need to develop highly effective antibacterial materials to eliminate the increasingly serious contamination of drug-resistant bacteria....Bacterial pathogens pose a serious threat to human health,and there is an urgent need to develop highly effective antibacterial materials to eliminate the increasingly serious contamination of drug-resistant bacteria.Here,a Cu-doped ZIF-8 particle with unsaturated copper exhibits high peroxidase-like activity.99.998%antibacterial efficiency against S.aureus can be achieved for 30 min at a low concentration of 50μg·mL^(−1),as well as complete sterilization against E.coli(up to 8 log).99.999%antibacterial efficiency against Methicillin-resistant Staphylococcus aureus can be achieved,performing orders of magnitude higher than Vancomycin.The mechanism shows that the unsaturated Cu-Nx sites are enzyme-like active centers,which could promote the consumption of bacteria reducing substances by H_(2)O_(2),and the generated*OH further aggravates bacterial oxidative stress and membrane damage.More importantly,the oxidation activity of adsorbed oxygen species on Cu-ZIF-8 is enhanced by charge transfer and structural changes between the ligand and copper center like natural enzymes.Cu-doped ZIF-8 with peroxidase-like activity shows great potential in antibacterial application and the revealed catalytic mechanism is helpful for understanding the high antibacterial activity of nanoparticles with Cu-Nx sites.展开更多
Targeted construction of new covalent organic frameworks(COFs)with specific purposes and rationalities to build colorimetric assay platform for environmental pollutant monitoring have attracted increasing interest.How...Targeted construction of new covalent organic frameworks(COFs)with specific purposes and rationalities to build colorimetric assay platform for environmental pollutant monitoring have attracted increasing interest.However,it is still challenging due to lack of available coordination sites inside COFs pores and only a slight bonding ability for anchoring metal.In this work,a two-dimensional(2D)COFs(termed as Tz-COF)with high crystallinity,excellent chemical stability,and abundant sulfur coordination in its skeletons was synthesized and used for the confined growth of Au NPs.It was found that the Au NPs showed significant dispersibility for the support of Tz-COF.The proposed Tz-COF@Au NPs possessed outstanding Hg^(2+)-activated peroxidase-like activity benefited from physicochemical properties of gold amalgam and synergistic effect between COFs and Au NPs to oxidize chromogenic substrate.Based on highly efficient activity and distinctive color evolution,the strategy for detecting Hg^(2+)was developed and successfully applied to determine the content of Hg^(2+)in real environmental samples.This work manifests that a potential strategy to establish a colorimetric assay platform for environmental pollutant monitoring based on the targeted manufacturing of novel COFs with specific functions.展开更多
In recent years, nanozymes have received more and more attention, but the low activity limits the development of nanozymes. Therefore, the design and development of efficient nanozymes is still a major challenge for r...In recent years, nanozymes have received more and more attention, but the low activity limits the development of nanozymes. Therefore, the design and development of efficient nanozymes is still a major challenge for researchers. Herein, the Fe,N co-doped ultrathin hollow carbon framework(Fe,N-UHCF) exhibit ultra-high peroxidase-like activity. The specific activity of Fe,N-UHCF nanozyme is as high as 36.6 U/mg,which is much higher than almost all of other reported nanozymes. In practical applications, the Fe,N-UHCF show good antibacterial effects.展开更多
The overuse of antibiotics has led to the severe contamination of water bodies,posing a considerable hazard to human health.Therefore,the development of an accurate and rapid point-of-care testing(POCT)platform for th...The overuse of antibiotics has led to the severe contamination of water bodies,posing a considerable hazard to human health.Therefore,the development of an accurate and rapid point-of-care testing(POCT)platform for the quantitative detection of antibiotics is necessary.In this study,Cerium oxide(CeO_(2))and Ferrosoferric oxide(Fe_(3)O_(4))nanoparticles were simultaneously encapsulated into N-doped nanofibrous carbon microspheres to form of a novel nanozyme(CeFe-NCMzyme)with a porous structure,high surface area,and N-doped carbon material properties,leading to a considerable enhancement of the peroxidase(POD)-like activity compared with that of the CeO_(2)or Fe3O4 nanoparticles alone.The POD-like activity of CeFe-NCMzyme can be quenched using L-Cysteine(Cys)and subsequently restored by the addition of a quinolone antibiotic(norfloxacin,NOR).Therefore,CeFe-NCMzyme was used as a colorimetric sensor to detect NOR via an“On-Off”model of POD-like activity.The sensor possessed a wide linear range of 0.05–20.0μM(R^(2)=0.9910)with a detection limit of 35.70 nM.Furthermore,a smartphone-assisted POCT platform with CeFe-NCMzyme was fabricated for quantitative detection of NOR based on RGB analysis.With the use of the POCT platform,a linear range of 0.1–20.0μM and a detection limit of 54.10 nM were obtained.The spiked recoveries in the water samples were ranged from 97.73%to 102.01%,and the sensor exhibited good accuracy and acceptable reliability.This study provides a portable POCT platform for the on-site and quantitative monitoring of quinolone antibiotics in real samples,particularly in resource-constrained settings.展开更多
Redox nanozymes offer an appealing reactive oxygen species(Ros)-based antibacterial strategy via disrupting intracellular homeostasis,however,they still face many obstacles such as low enzymic activity and irreversibl...Redox nanozymes offer an appealing reactive oxygen species(Ros)-based antibacterial strategy via disrupting intracellular homeostasis,however,they still face many obstacles such as low enzymic activity and irreversible loss of catalytic active center.Meanwhile,the antioxidant glutathione(GSH)overexpressed in infected sites would limit the therapy efficiency.Herein,we develop a multifunctional nanozyme based on copper(l)(Cut)ion doped MoO_(3-x)(Cut-MoO_(3-x))by a simple yet efficient oxygen vacancy-reduced strategy without any pretreatment or additional agents.The resultant Cu^(+)-MoO_(3-x) hybrid possesses enhanced peroxidase-like(POD-like)activity,rapid GSH-depleting function and biodegradable ability.It can achieve highly efficient elimination of Pseudomonas aeruginosa(P.aeruginosa)via disrupting cellular redox balance.展开更多
The residues of organophosphorus pesticide(OPs)on fruits and vegetables pose a threat to human health,so it is very meaningful to explore simple and fast detect methods for OPs residual.In this work,nickel ferrite/nic...The residues of organophosphorus pesticide(OPs)on fruits and vegetables pose a threat to human health,so it is very meaningful to explore simple and fast detect methods for OPs residual.In this work,nickel ferrite/nickel oxide nanoparticles co-loaded three-dimensional reduced graphene oxide(3DRGONiFe2O4/NiO NPs),as a new low cost nanocomposite,was prepared.Based on its high performance mimetic peroxidase activity,a colorimetric method for the detection of OPs has been developed.Dichlorvos was chosen as model compounds to evaluate the detection performance.The detection linear range for dichlorvos is from 50μg/mL to 2.5×10^4μg/mL with a detection limit of 10μg/mL.Furthermore,a test paper can be developed based on the 3 DRGO-NiFe2O4/NiO NPs for visual detection of dichlorvos,and the image information of the paper sensor can be converted into digital signal and quantitative detection by a smartphone.Notably,this method can also be used to detect dichlorvos in real samples,including vegetables and fruits.Thus,the developed naked assay holds great potential in simple,inexpensive and rapid detection of OPs in fruit and vegetable samples.展开更多
In recent years,Fe_(3)O_(4)nanomaterials have received much attention in analytical chemistry due to their excellent magnetic and peroxidase-like activity.As the catalytic characteristics of Fe_(3)O_(4)nanomaterials i...In recent years,Fe_(3)O_(4)nanomaterials have received much attention in analytical chemistry due to their excellent magnetic and peroxidase-like activity.As the catalytic characteristics of Fe_(3)O_(4)nanomaterials is similar to those of horseradish peroxidase(HRP),Fe_(3)O_(4)nanomaterials are also used as peroxidase mimics and have achieved a certain development in many fields based on latest research results.To improve the stability and catalytic ability of simple Fe_(3)O_(4)nanomaterials,various modification strategies of Fe_(3)O_(4)nanomaterials have been developed.The recent advances of these strategies have been presented and discussed.In addition,this paper introduces the application of Fe_(3)O_(4)nanozymes in the detection of food and industrial pollutants,as well as in the field of biosafety.展开更多
基金support from the National Natural Science Foundation of China(No.82072324)the National Key R&D Program of China(No.2019YFA0709200)+1 种基金National Natural Science Foundation of China Foundation of Innovative Research Group grant(No.22121003)the Chongqing Special Key Project of Technological Innovation and Application Development(No.cstc2019jscx-gksbX0053).
文摘During criminal case investigations,blood evidence tracing is critical for criminal investigation.However,the blood stains are often cleaned or covered up after the crime,resulting in trace residue and difficult tracking.Therefore,a highly sensitive and specific method for the rapid detection of human blood stains remains urgent.To solve this problem,we established a nanozyme-based strip for rapid detection of blood evidence with high sensitivity and specificity.To construct reliable nanozyme strips,we synthesized CoFe_(2)O_(4) nanozymes with high peroxidase-like activity by scaling up to gram level,which can be supplied for six million tests,and conjugated antibody as a detection probe in nanozyme strip.The developed CoFe_(2)O_(4) nanozyme strip can detect human hemoglobin(HGB)at a concentration as low as 1 ng/mL,which is 100 times lower than the commercially available colloidal gold strips(100 ng/mL).Moreover,this CoFe_(2)O_(4) nanozyme strip showed high generality on 12 substrates and high specificity to human HGB among 13 animal blood samples.Finally,we applied the developed CoFe_(2)O_(4) nanozyme strip to successfully detect blood stains in three real cases,where the current commercial colloidal gold strip failed to do.The results suggest that the CoFe_(2)O_(4) nanozyme strip can be used as an effective on-scene detection method for human blood stains,and can further be used as a long-term preserved material evidence for traceability inquiry.
基金The authors gratefully acknowledge the financial support of the Fundamental Research Funds for the Central Universities(CCNU20TS013)the National Natural Science Foundation of China(No.21503273)the Program of Introducing Talents of Discipline to Universities of China(111 program,B17019)and the Recruitment Program of Global Youth Experts of China.
文摘Although nanozymes have been widely developed,accurate design of highly active sites at the atomic level to mimic the electronic and geometrical structure of enzymes and the exploration of underlying mechanisms still face significant challenges.Herein,two functional groups with opposite electron modulation abilities(nitro and amino)were introduced into the metal–organic frameworks(MIL-101(Fe))to tune the atomically dispersed metal sites and thus regulate the enzymelike activity.Notably,the functionalization of nitro can enhance the peroxidase(POD)-like activity of MIL-101(Fe),while the amino is poles apart.Theoretical calculations demonstrate that the introduction of nitro can not only regulate the geometry of adsorbed intermediates but also improve the electronic structure of metal active sites.Benefiting from both geometric and electronic effects,the nitro-functionalized MIL-101(Fe)with a low reaction energy barrier for the HO*formation exhibits a superior POD-like activity.As a concept of the application,a nitro-functionalized MIL-101(Fe)-based biosensor was elaborately applied for the sensitive detection of acetylcholinesterase activity in the range of 0.2–50 mU mL−1 with a limit of detection of 0.14 mU mL−1.Moreover,the detection of organophosphorus pesticides was also achieved.This work not only opens up new prospects for the rational design of highly active nanozymes at the atomic scale but also enhances the performance of nanozyme-based biosensors.
基金support from the NSFC(21705141,22076161,21675140,21575124)the Green Yang Jinfeng Talent Project of Yangzhou+1 种基金the High-end talent Support Program of Yangzhou Universitythe Interdisciplinary Research Foundation for Chemistry Discipline of Targeted Support of Yangzhou University(yzuxk202009)
文摘A new ratiometric fluorescent sensor based on the bifunctional carbon quantum dots(CQDs)@metal-organic framework(MOF)nanocomposite possessing peroxidase-mimicking catalytic and luminescent characteristics was developed for hydrogen peroxide(H_(2)O_(2))and cholesterol detection.The incorporation of fluorescent CQDs into the cavities of MIL-101(Fe)MOF with peroxidase-like activities endows the nanocomposite with bifunctional properties.The CQDs@MOF can oxidize o-phenylene-diamine to 2,3-diaminophenolazine by H_(2)O_(2)with yellow fluorescence(556 nm).Meantime,the intrinsic fluorescence signal(455 nm)of CQDs@MOF is inhibited due to the inner filter effect.Therefore,the ratio of the fluorescent intensity is employed as the signal output to construct the H_(2)O_(2)ratiometric biosensor.In addition,the cholesterol can be determined by the ratiometric sensor with high sensitivity.In addition,the total cholesterol in human serum is determined with high accuracy using our ratiometric biosensor.This ratiometric fluorescent platform based on the bifunctional CQDs@MOF provides new insights in the field of bio-sensing.
基金the National Natural Science Foundation of China(Nos.21876099,22106088,and 22276110)Key Research&Developmental Program of Shandong Province(No.2021CXGC011202)Fundamental Research Funds of Shandong University(No.zy202102).
文摘Nanozyme antibacterial agents with high enzyme-like catalytic activity and strong bacteria-binding ability have provided an alternative method to efficiently disinfect drug-resistance microorganism.Herein,the carbon nitride quantum dots(CNQDs)nanozymes with high nitrogen vacancies(NVs)were mass-productively prepared by a simple ultrasonic-crushing method assisted by propylene glycol.It was found that the NVs of CNQDs were stemmed from the selective breaking of surface N-(C)_(2)sites,accounting for 6.2%.Experiments and density functional theory(DFT)simulations have demonstrated that the presence of NVs can alter the local electron distribution and extend theπ-electron delocalization to enhance the peroxidase-like activity.Biocompatible CNQDs could enter inside microorganisms by diffusion and elevate the bacteria-binding ability,which enhanced the accurate and rapid attack of·OH to the microorganisms.The sterilization rate of CNQDs against Gram-negative bacteria(E.coli),Gram-positive bacteria(S.aureus,B.subtilis),fungi(R.solani)reaches more than 99%.Thus,this work showed great potential for engineered nanozymes for broad-spectrum antibacterial in biomedicine and environmental protection.
基金Financial support was provided by the National Natural Science Foundation of China(Nos.21871249,21673223,21977091,21431007,21533008,and 21820102009)the Key Program of Frontier of Sciences,CAS QYZDJ-SSW-SLH052.
文摘Artificial enzymes have provided great antimicrobial activity to combat wound infection.However,the lack of tissue repair capability compromised their treatment effect.Therefore,development of novel artificial enzyme concurrently with the excellent antibacterial activity and the property of promoting wound healing are required.Here,we demonstrated the hydrogel-based artificial enzyme composed of copper and amino acids possessed intrinsic peroxidase-like catalytic activity,which could combat wound pathogen effectively and accelerate wound healing by stimulating angiogenesis and collagen deposition.Furthermore,the system possesses good biocompatibility for practical application.The synergic effect of the hydrogel-based artificial enzyme promises the system as a new paradigm in bacteria-infected wound healing therapy.
基金financially supported by the National Natural Science Foundation of China(22076041,22076042)the Key Research and Development Program of Hubei Province,China(2023BAB134).
文摘The controllable growth of metal nanoparticles on nanomaterials is becoming an effective strategy for developing nanocomposites with designated performance.Herein,a simple and mild strategy for the in situ growth of Pt–Pd bimetallic nanoparticles on covalent organic frameworks(COFs)to regulate the nanozyme activity was designed for colorimetric detection of hydrogen peroxide(H2O2)and glutathione(GSH).The COFs not only offer sufficient loading sites for the uniform dispersion of Pt–Pd bimetallic nanoparticles,but also increase the adsorption of substrate to promote the catalytic reaction.With the bimetallic synergistic effect of Pt–Pd nanoparticles,the prepared multifunctional nanozyme(Pt–Pd/COFs nanozyme)simultaneously exhibited superior peroxidase(POD)-like activity and oxidase(OXD)-like activity.Using the multifunctional nanozyme,a colorimetric sensing system was constructed for sensitive detection of H2O2 and GSH,with the wide linear ranges of 5–1000µmol/L and 1–40µmol/L,and the detection limits were 1.14μmol/L and 0.43μmol/L,respectively.It was successfully used for the detection of real samples in environmental water and serum,providing a simple method for disease diagnosis and environmental monitoring.
基金the National Natural Science Foundation of China(Nos.51872030,51631001,51902023,51702016,and 22175048)Beijing Institute of Technology Research Fund Program for Young Scholars.
文摘Carbon-based single-atom catalysts(SACs)have been widely studied in the field of biomedicine due to their excellent catalytic performance.However,carbon-based SACs usually aggregate during pyrolysis,which leads to the reduction of catalytic activity.Here,we describe a method to improve the monodispersion of SACs using silicon dioxide as a protective layer.The decoration of silicon dioxide serves as a buffer layer for individual nanoparticles,which is not destroyed during the pyrolysis process,ensuring the single-particle dispersion of the nanoparticles after etching.This approach increased the hydroxyl groups on the surface of Fe-SAC(Fe-SAC-SE)and improved its water solubility,resulting in a four times enhancement of the peroxidase(POD)-like activity of Fe-SAC-SE(58.4 U/mg)than that of non-protected SACs(13.9 U/mg).The SiO_(2)-protection approach could also improve the catalytic activities of SACs with other metals such as Mn,Co,Ni,and Cu,indicating its generality for SACs preparation.Taking advantage of the high POD-like activity,photothermal properties,and large specific surface area of Fe-SAC-SE,we constructed a synergistic therapeutic system(Fe-SAC-SE@DOX@PEG)for combining the photothermal therapy,catalytic therapy,and chemotherapy.It was verified that the photothermal properties of Fe-SAC-SE@DOX@PEG could effectively improve its POD-like activity,exhibiting excellent tumor-killing performance at the cellular level.This work may provide a general approach to improve the performances of SACs for disease therapy and diagnosis.
基金supported by the National Key R&D Program of China(No.2022YFC3702800)Beijing Natural Science Foundation(No.2232017)the research fund of State Key Laboratory of Mesoscience and Engineering(Nos.MESO-23-A07,and MESO-23-T02).
文摘Bacterial pathogens pose a serious threat to human health,and there is an urgent need to develop highly effective antibacterial materials to eliminate the increasingly serious contamination of drug-resistant bacteria.Here,a Cu-doped ZIF-8 particle with unsaturated copper exhibits high peroxidase-like activity.99.998%antibacterial efficiency against S.aureus can be achieved for 30 min at a low concentration of 50μg·mL^(−1),as well as complete sterilization against E.coli(up to 8 log).99.999%antibacterial efficiency against Methicillin-resistant Staphylococcus aureus can be achieved,performing orders of magnitude higher than Vancomycin.The mechanism shows that the unsaturated Cu-Nx sites are enzyme-like active centers,which could promote the consumption of bacteria reducing substances by H_(2)O_(2),and the generated*OH further aggravates bacterial oxidative stress and membrane damage.More importantly,the oxidation activity of adsorbed oxygen species on Cu-ZIF-8 is enhanced by charge transfer and structural changes between the ligand and copper center like natural enzymes.Cu-doped ZIF-8 with peroxidase-like activity shows great potential in antibacterial application and the revealed catalytic mechanism is helpful for understanding the high antibacterial activity of nanoparticles with Cu-Nx sites.
基金supported by the National Natural Science Foundation of China(Nos.22274021,21974021 and 22036001).
文摘Targeted construction of new covalent organic frameworks(COFs)with specific purposes and rationalities to build colorimetric assay platform for environmental pollutant monitoring have attracted increasing interest.However,it is still challenging due to lack of available coordination sites inside COFs pores and only a slight bonding ability for anchoring metal.In this work,a two-dimensional(2D)COFs(termed as Tz-COF)with high crystallinity,excellent chemical stability,and abundant sulfur coordination in its skeletons was synthesized and used for the confined growth of Au NPs.It was found that the Au NPs showed significant dispersibility for the support of Tz-COF.The proposed Tz-COF@Au NPs possessed outstanding Hg^(2+)-activated peroxidase-like activity benefited from physicochemical properties of gold amalgam and synergistic effect between COFs and Au NPs to oxidize chromogenic substrate.Based on highly efficient activity and distinctive color evolution,the strategy for detecting Hg^(2+)was developed and successfully applied to determine the content of Hg^(2+)in real environmental samples.This work manifests that a potential strategy to establish a colorimetric assay platform for environmental pollutant monitoring based on the targeted manufacturing of novel COFs with specific functions.
基金supported by the National Natural Science Foundation of China(NSFC,Nos.21671149,21571140,21531005 and 21703156)the 973 Program(No.2014CB845601)+3 种基金the Program for Innovative Research Team in University of Tianjin(No.TD13–5074)the Natural Science Foundation of Tianjin(No.18JCQNJC76000)the Science&Technology Development Fund of Tianjin Education Commission for Higher Education(No.2021KJ190)the Jiangsu Provincial Double-Innovation Doctor Program(No.02300053)。
文摘In recent years, nanozymes have received more and more attention, but the low activity limits the development of nanozymes. Therefore, the design and development of efficient nanozymes is still a major challenge for researchers. Herein, the Fe,N co-doped ultrathin hollow carbon framework(Fe,N-UHCF) exhibit ultra-high peroxidase-like activity. The specific activity of Fe,N-UHCF nanozyme is as high as 36.6 U/mg,which is much higher than almost all of other reported nanozymes. In practical applications, the Fe,N-UHCF show good antibacterial effects.
基金This work was financially supported by Natural Science Foundation of Jiangxi Province(Grant Nos.:20224ACB203016 and 20224BAB203022)Science and Technology Research Project of Jiangxi Provincial Department of Education(Grant No.:GJJ2201322)+1 种基金the National Natural Science Foundation of China(Grant Nos.:32060577 and 32360619)Natural Science Foundation for Distinguished Young Scholars of Hunan Province(Gtant No.:2023JJ10099).
文摘The overuse of antibiotics has led to the severe contamination of water bodies,posing a considerable hazard to human health.Therefore,the development of an accurate and rapid point-of-care testing(POCT)platform for the quantitative detection of antibiotics is necessary.In this study,Cerium oxide(CeO_(2))and Ferrosoferric oxide(Fe_(3)O_(4))nanoparticles were simultaneously encapsulated into N-doped nanofibrous carbon microspheres to form of a novel nanozyme(CeFe-NCMzyme)with a porous structure,high surface area,and N-doped carbon material properties,leading to a considerable enhancement of the peroxidase(POD)-like activity compared with that of the CeO_(2)or Fe3O4 nanoparticles alone.The POD-like activity of CeFe-NCMzyme can be quenched using L-Cysteine(Cys)and subsequently restored by the addition of a quinolone antibiotic(norfloxacin,NOR).Therefore,CeFe-NCMzyme was used as a colorimetric sensor to detect NOR via an“On-Off”model of POD-like activity.The sensor possessed a wide linear range of 0.05–20.0μM(R^(2)=0.9910)with a detection limit of 35.70 nM.Furthermore,a smartphone-assisted POCT platform with CeFe-NCMzyme was fabricated for quantitative detection of NOR based on RGB analysis.With the use of the POCT platform,a linear range of 0.1–20.0μM and a detection limit of 54.10 nM were obtained.The spiked recoveries in the water samples were ranged from 97.73%to 102.01%,and the sensor exhibited good accuracy and acceptable reliability.This study provides a portable POCT platform for the on-site and quantitative monitoring of quinolone antibiotics in real samples,particularly in resource-constrained settings.
基金supported by the National Natural Science Foundation of China(Nos.22305134 and 22274084)Natural Science Foundation for Distinguished Young Scholars of Shandong Province(ZR2021JQ04)Taishan Scholars Program of Shandong Province(No.tsqn 201909088).
文摘Redox nanozymes offer an appealing reactive oxygen species(Ros)-based antibacterial strategy via disrupting intracellular homeostasis,however,they still face many obstacles such as low enzymic activity and irreversible loss of catalytic active center.Meanwhile,the antioxidant glutathione(GSH)overexpressed in infected sites would limit the therapy efficiency.Herein,we develop a multifunctional nanozyme based on copper(l)(Cut)ion doped MoO_(3-x)(Cut-MoO_(3-x))by a simple yet efficient oxygen vacancy-reduced strategy without any pretreatment or additional agents.The resultant Cu^(+)-MoO_(3-x) hybrid possesses enhanced peroxidase-like(POD-like)activity,rapid GSH-depleting function and biodegradable ability.It can achieve highly efficient elimination of Pseudomonas aeruginosa(P.aeruginosa)via disrupting cellular redox balance.
基金financially supported by the National Natural Science Foundation of China (Nos.21874061,21207057,21405159, 21505061)the Fundamental Research Funds for the Central Universities (Nos.lzujbky-2016-43,lzujbky-2018-80)
文摘The residues of organophosphorus pesticide(OPs)on fruits and vegetables pose a threat to human health,so it is very meaningful to explore simple and fast detect methods for OPs residual.In this work,nickel ferrite/nickel oxide nanoparticles co-loaded three-dimensional reduced graphene oxide(3DRGONiFe2O4/NiO NPs),as a new low cost nanocomposite,was prepared.Based on its high performance mimetic peroxidase activity,a colorimetric method for the detection of OPs has been developed.Dichlorvos was chosen as model compounds to evaluate the detection performance.The detection linear range for dichlorvos is from 50μg/mL to 2.5×10^4μg/mL with a detection limit of 10μg/mL.Furthermore,a test paper can be developed based on the 3 DRGO-NiFe2O4/NiO NPs for visual detection of dichlorvos,and the image information of the paper sensor can be converted into digital signal and quantitative detection by a smartphone.Notably,this method can also be used to detect dichlorvos in real samples,including vegetables and fruits.Thus,the developed naked assay holds great potential in simple,inexpensive and rapid detection of OPs in fruit and vegetable samples.
基金the financial support from the National Natural Science Foundation of China(Nos.31901799,21705060,21605105 and 32001804)the Natural Science Foundation of Jiangsu Province,China(Nos.BK20211340 and BK20180979)+1 种基金Opening Project of Key Laboratory of Impurity Spectrum of Chemical Drug,China(No.NMPA-KLIPCD-2020-09)the Emerging science and technology innovation team funding of JUST(No.1182921902)。
文摘In recent years,Fe_(3)O_(4)nanomaterials have received much attention in analytical chemistry due to their excellent magnetic and peroxidase-like activity.As the catalytic characteristics of Fe_(3)O_(4)nanomaterials is similar to those of horseradish peroxidase(HRP),Fe_(3)O_(4)nanomaterials are also used as peroxidase mimics and have achieved a certain development in many fields based on latest research results.To improve the stability and catalytic ability of simple Fe_(3)O_(4)nanomaterials,various modification strategies of Fe_(3)O_(4)nanomaterials have been developed.The recent advances of these strategies have been presented and discussed.In addition,this paper introduces the application of Fe_(3)O_(4)nanozymes in the detection of food and industrial pollutants,as well as in the field of biosafety.
