Noble metal clusters is an emerging class of fluorescent probes, avoiding most of the drawbacks of common fluorescent compounds, and they are simple to prepare and have good water solubility, good biocompatibility and...Noble metal clusters is an emerging class of fluorescent probes, avoiding most of the drawbacks of common fluorescent compounds, and they are simple to prepare and have good water solubility, good biocompatibility and excellent fluorescence properties. In this study, we have explored the synthesis of the cytidine mediated gold-silver nanoclusters （AuAg NCs） and applied it for both in vitro cellular imaging and tumor in vivo detection. Experimental results show that the as-prepared AuAg NCs can be used as a sensitive fluorescent probe for cancer cells/tissue de- tection. Especially, it is evident that under the relevant light irradiation with the wavelength of 488 nm, obviously bright fluorescence signal could be readily detected from focus location of inoculating tumor mouse, implying its possible application for the effective in vivo tumor bioimaging.展开更多
The mechanism of addition of separate atoms to a growing center is considered with application of model of a pair interpenetration of atoms. Features of geometrical model are related with the electronic structure of a...The mechanism of addition of separate atoms to a growing center is considered with application of model of a pair interpenetration of atoms. Features of geometrical model are related with the electronic structure of atoms and the Pauli＇s exclusion principle. The forces providing self-organization of atoms in the bulk of a condensed substance are shown. The calculated interatomic distances in graphite and alloys of gold with silver coincide with those known from experiments with accuracy of 0.1%.展开更多
Plasmonic metal nanomaterials with intrinsic surface–enhanced Raman scattering(SERS)and photothermal properties,especially AuAg nanoalloys with both the outstanding merits of Au and Ag nanocrystals,show huge applicat...Plasmonic metal nanomaterials with intrinsic surface–enhanced Raman scattering(SERS)and photothermal properties,especially AuAg nanoalloys with both the outstanding merits of Au and Ag nanocrystals,show huge application prospects in bacterial theranostics.However,the direct exposure of AuAg nanoalloys in external conditions probably cause undesirable reactions and poisonous metal ion leakage during SERS detection and photothermal antibacterial therapy process,which severely hinder bacterial theranostics applications.Herein,we report an ultrastable graphene–isolated AuAg nanoalloy(GAA)with AuAg core confined in few–layer graphitic shell as a versatile platform for bacterial detection and therapy.The encapsulation of graphene ensures the good stability of AuAg core,that its superior SERS and photothermal properties are therefore further guaranteed.GAA is used for SERS detection of two vital bacterial biomarkers(including corrosive cyanide and pyocyanin),exhibiting good SERS quantitative and multiplexing ability.GAA is further used for photothermal antibacterial therapy application,and ultrahigh antibacterial efficacies for both Gram–negative Escherichia coli and Gram–positive Staphylococcus aureus are achieved under 808 nm laser irradiation.This work proposes a valuable method to develop robust bacterial theranostic platform.展开更多
The redox property of the ultrasmall coinage nanoclusters(with several to tens of Au/Ag atoms)has elucidated the electrontransfer capacity of nanoclusters,has been successfully utilized in a variety of redox conversio...The redox property of the ultrasmall coinage nanoclusters(with several to tens of Au/Ag atoms)has elucidated the electrontransfer capacity of nanoclusters,has been successfully utilized in a variety of redox conversions(such as from CO_(2)to CO).Nevertheless,their biological applications are mainly restricted by the scarcity of atomically precise,water-soluble metal nanoclusters,the limited application(mainly on the decomposition of H_(2)O_(2)in these days).Herein,mercaptosuccinic acid(MSA)protected ultrasmall alloy AuAg nanoclusters were prepared,the main product was determined[Au_(3)Ag_(5)(MSA)_(3)]−by electrospray ionization mass spectrometry(ESI-MS).The clusters can not only mediate the decomposition of H_(2)O_(2)to generate hydroxyl radicals,but is also able to mediate the reduction of nicotinamide adenine dinucleotide(NAD)to its reduced form of NADH.This is the first time that the atomically precise metal nanoclusters were used to mediate the coenzyme reduction.The preliminary mechanistic insights imply the reaction to be driven by the hydrogen bonding between the carboxylic groups(on the surface of MSA)and the amino N–H bonds(on NAD).In this context,the presence of the carboxylic groups,the sub-nanometer size regime(~1 nm),the synergistic effect of the Au-Ag clusters are pre-requisite to the NAD reduction.展开更多
文摘Noble metal clusters is an emerging class of fluorescent probes, avoiding most of the drawbacks of common fluorescent compounds, and they are simple to prepare and have good water solubility, good biocompatibility and excellent fluorescence properties. In this study, we have explored the synthesis of the cytidine mediated gold-silver nanoclusters （AuAg NCs） and applied it for both in vitro cellular imaging and tumor in vivo detection. Experimental results show that the as-prepared AuAg NCs can be used as a sensitive fluorescent probe for cancer cells/tissue de- tection. Especially, it is evident that under the relevant light irradiation with the wavelength of 488 nm, obviously bright fluorescence signal could be readily detected from focus location of inoculating tumor mouse, implying its possible application for the effective in vivo tumor bioimaging.
文摘The mechanism of addition of separate atoms to a growing center is considered with application of model of a pair interpenetration of atoms. Features of geometrical model are related with the electronic structure of atoms and the Pauli＇s exclusion principle. The forces providing self-organization of atoms in the bulk of a condensed substance are shown. The calculated interatomic distances in graphite and alloys of gold with silver coincide with those known from experiments with accuracy of 0.1%.
基金funding support from the National Key Research and Development Program of China(Nos.2022YFC2403501,2020YFA0210800)National Natural Science Foundation of China(No.22225401)+1 种基金Science and Technology Innovation Program of Hunan Province(No.2020RC4017)China Postdoctoral Science Foundation(No.2021M701145)。
文摘Plasmonic metal nanomaterials with intrinsic surface–enhanced Raman scattering(SERS)and photothermal properties,especially AuAg nanoalloys with both the outstanding merits of Au and Ag nanocrystals,show huge application prospects in bacterial theranostics.However,the direct exposure of AuAg nanoalloys in external conditions probably cause undesirable reactions and poisonous metal ion leakage during SERS detection and photothermal antibacterial therapy process,which severely hinder bacterial theranostics applications.Herein,we report an ultrastable graphene–isolated AuAg nanoalloy(GAA)with AuAg core confined in few–layer graphitic shell as a versatile platform for bacterial detection and therapy.The encapsulation of graphene ensures the good stability of AuAg core,that its superior SERS and photothermal properties are therefore further guaranteed.GAA is used for SERS detection of two vital bacterial biomarkers(including corrosive cyanide and pyocyanin),exhibiting good SERS quantitative and multiplexing ability.GAA is further used for photothermal antibacterial therapy application,and ultrahigh antibacterial efficacies for both Gram–negative Escherichia coli and Gram–positive Staphylococcus aureus are achieved under 808 nm laser irradiation.This work proposes a valuable method to develop robust bacterial theranostic platform.
基金National Science Foundation of Anhui Province(No.2108085J08)the University Synergy Innovation Program of Anhui Province(No.GXXT-2021-023)the technical support of high-performance computing platform of Anhui University.
文摘The redox property of the ultrasmall coinage nanoclusters(with several to tens of Au/Ag atoms)has elucidated the electrontransfer capacity of nanoclusters,has been successfully utilized in a variety of redox conversions(such as from CO_(2)to CO).Nevertheless,their biological applications are mainly restricted by the scarcity of atomically precise,water-soluble metal nanoclusters,the limited application(mainly on the decomposition of H_(2)O_(2)in these days).Herein,mercaptosuccinic acid(MSA)protected ultrasmall alloy AuAg nanoclusters were prepared,the main product was determined[Au_(3)Ag_(5)(MSA)_(3)]−by electrospray ionization mass spectrometry(ESI-MS).The clusters can not only mediate the decomposition of H_(2)O_(2)to generate hydroxyl radicals,but is also able to mediate the reduction of nicotinamide adenine dinucleotide(NAD)to its reduced form of NADH.This is the first time that the atomically precise metal nanoclusters were used to mediate the coenzyme reduction.The preliminary mechanistic insights imply the reaction to be driven by the hydrogen bonding between the carboxylic groups(on the surface of MSA)and the amino N–H bonds(on NAD).In this context,the presence of the carboxylic groups,the sub-nanometer size regime(~1 nm),the synergistic effect of the Au-Ag clusters are pre-requisite to the NAD reduction.
