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
The presence of toxic mercury (Ⅱ) in water is an ever-growing problem on earth that has various harmful effect on human health and aquatic living organisms.Therefore,detection of mercury (Ⅱ) in water is very much cr...The presence of toxic mercury (Ⅱ) in water is an ever-growing problem on earth that has various harmful effect on human health and aquatic living organisms.Therefore,detection of mercury (Ⅱ) in water is very much crucial and several researches are going on in this topic.Metal-organic frameworks (MOFs) are considered as an effective device for sensing of toxic heavy metal ions in water.The tunable functionalities with large surface area of highly semiconducting MOFs enhance its activity towards fluorescence sensing.In this study,we are reporting one highly selective and sensitive luminescent sensor for the detection of mercury (Ⅱ) in water.A series of binary MOF composites were synthesized using in-situ solvothermal synthetic technique for fluorescence sensing of Hg^(2+)in water.The welldistributed graphitic carbon nitride quantum dots on porous zirconium-based MOF improve Hg^(2+)sensing activity in water owing to their great electronic and optical properties.The binary MOF composite (2) i.e.,the sensor exhibited excellent limit of detection (LOD) value of 2.4 nmol/L for Hg^(2+).The sensor also exhibited excellent performance for mercury (Ⅱ)detection in real water samples.The characterizations of the synthesized materials were done using various spectroscopic techniques and the fluorescence sensing mechanism was studied.展开更多
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.
文摘The presence of toxic mercury (Ⅱ) in water is an ever-growing problem on earth that has various harmful effect on human health and aquatic living organisms.Therefore,detection of mercury (Ⅱ) in water is very much crucial and several researches are going on in this topic.Metal-organic frameworks (MOFs) are considered as an effective device for sensing of toxic heavy metal ions in water.The tunable functionalities with large surface area of highly semiconducting MOFs enhance its activity towards fluorescence sensing.In this study,we are reporting one highly selective and sensitive luminescent sensor for the detection of mercury (Ⅱ) in water.A series of binary MOF composites were synthesized using in-situ solvothermal synthetic technique for fluorescence sensing of Hg^(2+)in water.The welldistributed graphitic carbon nitride quantum dots on porous zirconium-based MOF improve Hg^(2+)sensing activity in water owing to their great electronic and optical properties.The binary MOF composite (2) i.e.,the sensor exhibited excellent limit of detection (LOD) value of 2.4 nmol/L for Hg^(2+).The sensor also exhibited excellent performance for mercury (Ⅱ)detection in real water samples.The characterizations of the synthesized materials were done using various spectroscopic techniques and the fluorescence sensing mechanism was studied.
