Fluorescent nanomaterials have attracted much attention,due to their unique luminescent properties and promis-ing applications in biomedical areas.In this study,lignin basedfluorescent nanoparticles(LFNP)with high yiel...Fluorescent nanomaterials have attracted much attention,due to their unique luminescent properties and promis-ing applications in biomedical areas.In this study,lignin basedfluorescent nanoparticles(LFNP)with high yield(up to 32.4%)were prepared from lignin nanoparticles(LNP)by one-pot hydrothermal method with ethylene-diamine(EDA)and citric acid.Morphology and chemical structure of LFNP were investigated by SEM,FT-IR,and zeta potential,and it was found that the structure of LFNP changed with the increase of citric acid addition.LFNP showed the highestfluorescence intensity under UV excitation at wavelengths of 375–385 nm,with emis-sion wavelengths between 454–465 nm,and exhibited strong photoluminescence behavior.Meanwhile,with the increase of citric acid content,the energy gap(ΔE)gradually decreased from 3.87 to 3.14 eV,which corresponds to the gradual enhancement offluorescence performance.LFNP also exhibited excellent antioxidant activity,with DPPH free radical scavenging rate increased from 80.8%for LNP up to 96.7%for LFNP,confirming the great potential of these materials for application in biomedicine and cosmetic health care.展开更多
A series of boron- and phosphorus-doped silicon wafers are used to prepare a series of doped silicon nanocrystals (nc-Si) by high-energy ball milling with carboxylic acid-terminated surface. The sizes of the nc-Si s...A series of boron- and phosphorus-doped silicon wafers are used to prepare a series of doped silicon nanocrystals (nc-Si) by high-energy ball milling with carboxylic acid-terminated surface. The sizes of the nc-Si samples are demonstrated to be 〈 S nm. The doping levels of the nc-Si are found to be nonlinearly dependent on the original doping level of the wafers by x-ray photoelectron spectroscopy measurement. It is found that the nonlinear doping process will lead to the nonlinear chemical passivation and photoluminescence (I3L) intensity evolution. The doping, chemical passivation and PL mechanisms of the doped nc-Si samples prepared by mechanochemical synthesis are analyzed in detail.展开更多
Over the past decade, carbon dots have ignited a burst of interest in many different fields, including nanomedicine, solar energy, optoelectronics, energy storage,and sensing applications, owing to their excellent pho...Over the past decade, carbon dots have ignited a burst of interest in many different fields, including nanomedicine, solar energy, optoelectronics, energy storage,and sensing applications, owing to their excellent photoluminescence properties and the easiness to modify their optical properties through doping and functionalization. In this review, the synthesis, structural and optical properties,as well as photoluminescence mechanisms of carbon dots are first reviewed and summarized. Then, we describe a series of designs for carbon dot-based sensors and the different sensing mechanisms associated with them.Thereafter, we elaborate on recent research advances on carbon dot-based sensors for the selective and sensitive detection of a wide range of analytes, including heavy metals, cations, anions, biomolecules, biomarkers,nitroaromatic explosives, pollutants, vitamins, and drugs.Lastly, we provide a concluding perspective on the overall status, challenges, and future directions for the use of carbon dots in real-life sensing.展开更多
Carbonized polymer dots(CPDs)as one type of carbon dots have attracted widespread attention in recent years.The proposal of the“shell–core”structure of CPDs leads to further thinking about the association between t...Carbonized polymer dots(CPDs)as one type of carbon dots have attracted widespread attention in recent years.The proposal of the“shell–core”structure of CPDs leads to further thinking about the association between their special structures and luminescent properties.In recent years,great progress has been made in the field of CPD-based room-temperature phosphorescent materials.This review pays particular attention to how the special“core–shell”structure of CPDs influences the activation of roomtemperature phosphorescence(RTP).The strategies and vital factors to activate RTP for CPD-based materials in both solid state and water were reviewed in detail to elaborate on the effect of the special structure on RTP generation.Furthermore,some perspectives on the current challenges were also provided to guide the further development of CPD-based room-temperature phosphorescent materials.展开更多
基金This work was financially supported by National Natural Science Foundation of China(51903106)State Administration of Foreign Experts Affairs(G2021144006L).
文摘Fluorescent nanomaterials have attracted much attention,due to their unique luminescent properties and promis-ing applications in biomedical areas.In this study,lignin basedfluorescent nanoparticles(LFNP)with high yield(up to 32.4%)were prepared from lignin nanoparticles(LNP)by one-pot hydrothermal method with ethylene-diamine(EDA)and citric acid.Morphology and chemical structure of LFNP were investigated by SEM,FT-IR,and zeta potential,and it was found that the structure of LFNP changed with the increase of citric acid addition.LFNP showed the highestfluorescence intensity under UV excitation at wavelengths of 375–385 nm,with emis-sion wavelengths between 454–465 nm,and exhibited strong photoluminescence behavior.Meanwhile,with the increase of citric acid content,the energy gap(ΔE)gradually decreased from 3.87 to 3.14 eV,which corresponds to the gradual enhancement offluorescence performance.LFNP also exhibited excellent antioxidant activity,with DPPH free radical scavenging rate increased from 80.8%for LNP up to 96.7%for LFNP,confirming the great potential of these materials for application in biomedicine and cosmetic health care.
基金Supported by the National Natural Science Foundation of China under Grant No 61575216
文摘A series of boron- and phosphorus-doped silicon wafers are used to prepare a series of doped silicon nanocrystals (nc-Si) by high-energy ball milling with carboxylic acid-terminated surface. The sizes of the nc-Si samples are demonstrated to be 〈 S nm. The doping levels of the nc-Si are found to be nonlinearly dependent on the original doping level of the wafers by x-ray photoelectron spectroscopy measurement. It is found that the nonlinear doping process will lead to the nonlinear chemical passivation and photoluminescence (I3L) intensity evolution. The doping, chemical passivation and PL mechanisms of the doped nc-Si samples prepared by mechanochemical synthesis are analyzed in detail.
基金supported by NTUA*STAR Silicon Technologies Centre of Excellence under the program Grant (No.11235100003)Grants Tier 2 MOE2017-T2-2-002 (No.M402110000) from Ministry of Educationthe NRF-ANR Joint Call 2017 Research Grant (No. M419640000) from the National Research Foundation,Singapore
文摘Over the past decade, carbon dots have ignited a burst of interest in many different fields, including nanomedicine, solar energy, optoelectronics, energy storage,and sensing applications, owing to their excellent photoluminescence properties and the easiness to modify their optical properties through doping and functionalization. In this review, the synthesis, structural and optical properties,as well as photoluminescence mechanisms of carbon dots are first reviewed and summarized. Then, we describe a series of designs for carbon dot-based sensors and the different sensing mechanisms associated with them.Thereafter, we elaborate on recent research advances on carbon dot-based sensors for the selective and sensitive detection of a wide range of analytes, including heavy metals, cations, anions, biomolecules, biomarkers,nitroaromatic explosives, pollutants, vitamins, and drugs.Lastly, we provide a concluding perspective on the overall status, challenges, and future directions for the use of carbon dots in real-life sensing.
基金supported by the National Science Foundation of China(NSFC)under grant no.22035001.
文摘Carbonized polymer dots(CPDs)as one type of carbon dots have attracted widespread attention in recent years.The proposal of the“shell–core”structure of CPDs leads to further thinking about the association between their special structures and luminescent properties.In recent years,great progress has been made in the field of CPD-based room-temperature phosphorescent materials.This review pays particular attention to how the special“core–shell”structure of CPDs influences the activation of roomtemperature phosphorescence(RTP).The strategies and vital factors to activate RTP for CPD-based materials in both solid state and water were reviewed in detail to elaborate on the effect of the special structure on RTP generation.Furthermore,some perspectives on the current challenges were also provided to guide the further development of CPD-based room-temperature phosphorescent materials.