Ultrasmall gold nanoparticles(AuNPs)typically includes atomically precise gold nanoclusters(AuNCs)and AuNPs with a core size below 3 nm.Serving as a bridge between small molecules and traditional inorganic nanoparticl...Ultrasmall gold nanoparticles(AuNPs)typically includes atomically precise gold nanoclusters(AuNCs)and AuNPs with a core size below 3 nm.Serving as a bridge between small molecules and traditional inorganic nanoparticles,the ultrasmall AuNPs show the unique advantages of both small molecules(e.g.,rapid distribution,renal clearance,low non-specific organ accumulation)and nanoparticles(e.g.,long blood circulation and enhanced permeability and retention effect).The emergence of ultrasmall AuNPs creates significant opportunities to address many challenges in the health field including disease diagnosis,monitoring and treatment.Since the nano–bio interaction dictates the overall biological applications of the ultrasmall AuNPs,this review elucidates the recent advances in the biological interactions and imaging of ultrasmall AuNPs.We begin with the introduction of the factors that influence the cellular interactions of ultrasmall AuNPs.We then discuss the organ interactions,especially focus on the interactions of the liver and kidneys.We further present the recent advances in the tumor interactions of ultrasmall AuNPs.In addition,the imaging performance of the ultrasmall AuNPs is summarized and discussed.Finally,we summarize this review and provide some perspective on the future research direction of the ultrasmall AuNPs,aiming to accelerate their clinical translation.展开更多
Sorption between nanoparticles(NPs)and minerals may critically affect the migration of associated elements as well as the environmental impact of NPs.Since illite is widely present in soil,sediment,and water,we have e...Sorption between nanoparticles(NPs)and minerals may critically affect the migration of associated elements as well as the environmental impact of NPs.Since illite is widely present in soil,sediment,and water,we have experimentally investigated the sorption behavior of citrate-coated gold nanoparticles(AuNPs)as model NPs on illite under different pH and mineral mass conditions.We demonstrated that sorption of these negatively charged AuNPs strongly depended on the suspension pH.At pH above 8,which coincided with the apparent point of zero charge(pH 7.9)of our illite sample,only marginal sorption of AuNPs was observed.At pH 3-8,significant sorption of AuNPs on illite was found,with almost complete sorption occurring at more acidic conditions(pH 3-4).TEM observations revealed that sorption took place through the attachment AuNPs on illite edges.At pH 2,AuNPs mostly formed chain-like fused structures and precipitated out of the suspension.Based upon the above pH dependence,residual organic ligand content after sorption,and complementary sorption results with positively charged AuNPs,we conclude that the sorption process is mainly driven by the electrostatic attraction between negatively charged AuNPs and positively charged illite edges,with possible competitive involvement of citrate molecules.We expect that our findings will improve our understanding of NP-mineral interaction and the environmental fate of NPs.展开更多
With the support of the National Natural Science Foundation of China,Prof.Zhang Tao(张涛)and Prof.Wang Junhu’s group at the Laboratory of Catalysts and New Materials for Aerospace,Dalian Institute of Chemical Physics...With the support of the National Natural Science Foundation of China,Prof.Zhang Tao(张涛)and Prof.Wang Junhu’s group at the Laboratory of Catalysts and New Materials for Aerospace,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,recently discovered a new type of strong metalsupport interaction(SMSI)between gold nanoparticles(NPs)and nonoxides,which was published in展开更多
Fluorous gold nanoparticle （Fluo-NP）, i.e. gold nanoparticle covered by fluorous ponytail （C8F17-） was pre- pared and found to self-assemble into supra-structures covered by carbohydrates （named supraF-NP）, due ...Fluorous gold nanoparticle （Fluo-NP）, i.e. gold nanoparticle covered by fluorous ponytail （C8F17-） was pre- pared and found to self-assemble into supra-structures covered by carbohydrates （named supraF-NP）, due to the strong fluorous interaction. More importantly, the re-dispersed supraF-NP （diameter around 200 nm） in water pro- vided an alternative strategy to detect carbohydrate-protein interaction in solution by naked eve.展开更多
Au/CdTe nanocomposites were prepared by electrostatic interaction between oppositely-charged gold （Au） and cadmium telluride （CdTe） nanoparticles. Au and CdTe nanoparticles were stabilized by 4-（dimethylamino）py...Au/CdTe nanocomposites were prepared by electrostatic interaction between oppositely-charged gold （Au） and cadmium telluride （CdTe） nanoparticles. Au and CdTe nanoparticles were stabilized by 4-（dimethylamino）pyridine （DMAP） and 3-mercaptopropionic acid to develop positive and negative charges on their surfaces in aqueous solutions, respectively. The red shifts of the surface plasmon absorptions with the increase of Au content indicate that the sizes of the nanocomposites expanded due to the complex formation. Mixing ratio of Au and CdTe nanoparticles controls the structure of the resulting composites effectively. Moreover, the sizes and shapes of the mixed nanoparticles are important parameters for the formation of metal/semiconductor nanocomposites. The Au/CdTe nanocomposites were characterized by small angle X-ray scattering technique （SAXS）, transmission electron microscopy （TEM）, cyclic voltammetry （CV） and X-ray photoelectron spectroscopy （XPS）.展开更多
Large Hollow nanoparticulate aggregates（LHNAs） based on albumin nanoparticles is a promising technology for developing dry powder inhaler（DPI） with good aerodynamic properties in order to provide a new drug delive...Large Hollow nanoparticulate aggregates（LHNAs） based on albumin nanoparticles is a promising technology for developing dry powder inhaler（DPI） with good aerodynamic properties in order to provide a new drug delivery system（DDS） for the treatment of lung disease. Improved understanding of molecular interactions could lead to prepare the DDS rationally. Therefore, this investigation utilized computations and experiments to reveal the mechanisms of budesonide（BUD） interactions with bovine serum albumin（BSA） at the molecular level. The molecular dynamics（MD） simulation revealed that there were three critical stable binding sites of BUD on BSA（P1, P2, P3） mainly by hydrophobic interaction and hydrogen bond. The energy decomposition of each residue to the whole BUD-BSA complex system in P1-P3 showed that nonpolar residues in or around the binding site played an important role in the binding of BUD to BSA. The molar ratio was close to 3 in preparations in drug-loading efficiency experiment, which was confirmed to the simulation results. The details of the binding sites from computation provided a guideline for the design of the BSA nanoparticles carrying BUD, which was prepared successfully at last. Combination of the MD simulation and experiment as well as the mechanism of the molecular interaction provided a solid theoretical basis for the preparation of BSA-LHNAs for DPI in the future.展开更多
A convenient colorimetric approach for visual detection of melamine in raw milk was realized by using gold nanoparticles(AuNPs)stabilized by an unsymmetrical terpyridyl zinc complex with a thymine fragment at one term...A convenient colorimetric approach for visual detection of melamine in raw milk was realized by using gold nanoparticles(AuNPs)stabilized by an unsymmetrical terpyridyl zinc complex with a thymine fragment at one terminal and a quaternary ammonium salt at the other.Even without pre-addition of melamine or relative additives,obvious color change from red to blue was observed by naked eye in the presence of trace amount of melamine,which was attributed to the alternation of aggregation state of AuNPs caused by the selective binding between the thymine fragment and melamine via triple hydrogenbonding interactions.Remarkably,the detection limit for melamine was as low as 2.4 ppb,providing a highly sensitive and efficient approach for the visual detection of melamine.展开更多
DNA-functionalized gold nanoparticles are one of the most versatile bionanomaterials for biomedical and clinical diagnosis. Herein, we discovered that the performance of DNAzyme cleaving the substrate is highly relate...DNA-functionalized gold nanoparticles are one of the most versatile bionanomaterials for biomedical and clinical diagnosis. Herein, we discovered that the performance of DNAzyme cleaving the substrate is highly related to its length. This intriguing phenomenon only appears at the interfaces of DNAfunctionalized gold nanoparticles. We systematically investigated the causes of this phenomenon. We conjectured that the DNAzyme with extended nucleotides that do not match its substrate strand is vulnerable to non-specific adsorption, electrostatic repulsion, and steric hindrance. Based on our improved understanding of this phenomenon, we have successfully developed a highly sensitive and specific amplifiable biosensor to detect human apurinic/apyrimidinic endonuclease 1.展开更多
Based on the host-guest molecular recognition capability of cucurbit[6]uril(CB[6])modified on the gold surface,sensitive spectrophotometric and electrochemical methods for the detection of metformin(MET)have been deve...Based on the host-guest molecular recognition capability of cucurbit[6]uril(CB[6])modified on the gold surface,sensitive spectrophotometric and electrochemical methods for the detection of metformin(MET)have been developed.The molecular recognition between cucurbit[7]uril(CB[7])or CB[6]and MET is initially demonstrated and the related recognition mechanism is further deliberated.First,CB[6]-modified gold nanoparticles(AuNPs/CB[6])were synthesized and then characterized by ultraviolet visible light spectrum(UV–vis)and transmission electron microscopy(TEM).The aggregation of Au NPs/CB[6]prompted by MET triggered changes of color and the absorption spectrum,that explored for the visual identification and spectrophotometric determination of MET.Under the optimized detection conditions,the UV–vis spectrometry had a good linear relationship in the range of 6–700μmol/L,and the detection limit was 2μmol/L.In addition,a single-layer CB[6]-modified gold electrode(GE-CB[6])detection system for MET was constructed.As the concentration of MET in the solution continues to increase,the charge transfer resistance(Rct)in the Nyquist diagram of the electrochemical impedance method(EIS)continues to increase.In the concentration range from 10 pmol/L to 20 nmol/L,the logarithm of the MET concentration has a good linear relationship with Rct,and the detection limit of this method is 1.35 pmol/L.Both methods have good concentration sensitivity to MET in different concentration ranges,providing a powerful tool for the detection of MET.展开更多
Gold nanoparticles （GNPs） have been widely used as probes and nanomaterials in certain biological and biomedical fields thanks to its special physical and chemical properties. However, it is still difficult to chara...Gold nanoparticles （GNPs） have been widely used as probes and nanomaterials in certain biological and biomedical fields thanks to its special physical and chemical properties. However, it is still difficult to characterize GNPs-bioconjugates in solution, which has greatly limited further bioapplications of GNPs. In this study, we reported a single particle method for characterizing GNPs- biomolecules in solution using resonance light scattering correlation spectroscopy （RLSCS）. The interaction of GNPs with bovine serum albumin （BSA） and thiol-modified oligonucletides were investigated.展开更多
Covalent organic frameworks(COFs)have lately emerged as a blooming class of potential materials for photocatalytic water splitting because of their high crystallinity,huge surface areas,and structural versatility.Howe...Covalent organic frameworks(COFs)have lately emerged as a blooming class of potential materials for photocatalytic water splitting because of their high crystallinity,huge surface areas,and structural versatility.However,the photocatalytic performance for most pure COFs face some limitations factors,such as the significant recombination of photogenerated carriers and slow charge transfer.Herein,a novel thioether-functionalized pyrene-based COF(S_(4)-COF)was effectively produced and chosen as a support for the immobilization of ultrafine gold nanoparticles(Au NPs).S_(4)-COF photocatalyst with Au as cocatalyst demonstrates remarkable photocatalytic activity with a H_(2) generation rate of 1377μmol g^(−1) h^(−1) under visible light(>420 nm),which is ca.4.5-fold increase comparing to that of pure S_(4)-COF(302μmol g^(−1) h^(−1)).Au NPs anchored on S_(4)-COF possess an ultrafine size distribution ranging from 1.75 to 6.25 nm with an average size centered at 3.8 nm,which benefits from the coordination interaction between thioether groups and Au.Meanwhile,the produced Au@S_(4)-COF can generate a stable photocatalytic H_(2) generation during the four recycles and preserve its crystallinity structure after the stability testing.The Au NPs anchored on the S_(4)-COF photocatalyst can greatly accelerate the separation of photogenerated carriers and increase charge transfer because of the combined function of Au NPs and thioether groups.Such a method can not only prevent the aggregation of Au NPs onto thioether-containing COFs to achieve long-term photostability but also allow uniform dispersion for an ordered structure of photocatalysts.This work provides a rational strategy for designing and preparing COF-based photocatalysts for solar-driven H_(2) production.展开更多
An indirect immunoassay for detecting antigen was developed. It was based on fluorescence resonance energy transfer (FRET) and quenching of gold nanoparticles. Bovine serum albumin (BSA) was chosen as model antigen. F...An indirect immunoassay for detecting antigen was developed. It was based on fluorescence resonance energy transfer (FRET) and quenching of gold nanoparticles. Bovine serum albumin (BSA) was chosen as model antigen. Fluorescein isothiocyanate (FITC) was attached to anti-BSA antibody (anti-BSA–FITC) as FRET donor, while BSA was conjugated to gold nanoparticles (GNPs–BSA) as FRET acceptor. The formation of anti-BSA–BSA immunocomplex resulted in the FRET between anti-BSA–FITC and GNPs–BSA. Thus, the fluorescence of FRET donor was quenched, and the decreasing fluorescence intensity responded linearly to the concentration of acceptor within the linear range. The concentration of BSA we obtained according to the stoichiometric ratio between BSA and GNPs. Following this approach, we were able to specifically detect BSA. The detection limit for BSA was 0.5 nM and the linear range of the assay was 2.9 - 43.5 nM. It had been successfully applied to specific detection of BSA in serum samples.展开更多
基金the National Natural Science Foundation of China(Grant 22022403 and 22274058)Fundamental Research Funds for the Central Universities.
文摘Ultrasmall gold nanoparticles(AuNPs)typically includes atomically precise gold nanoclusters(AuNCs)and AuNPs with a core size below 3 nm.Serving as a bridge between small molecules and traditional inorganic nanoparticles,the ultrasmall AuNPs show the unique advantages of both small molecules(e.g.,rapid distribution,renal clearance,low non-specific organ accumulation)and nanoparticles(e.g.,long blood circulation and enhanced permeability and retention effect).The emergence of ultrasmall AuNPs creates significant opportunities to address many challenges in the health field including disease diagnosis,monitoring and treatment.Since the nano–bio interaction dictates the overall biological applications of the ultrasmall AuNPs,this review elucidates the recent advances in the biological interactions and imaging of ultrasmall AuNPs.We begin with the introduction of the factors that influence the cellular interactions of ultrasmall AuNPs.We then discuss the organ interactions,especially focus on the interactions of the liver and kidneys.We further present the recent advances in the tumor interactions of ultrasmall AuNPs.In addition,the imaging performance of the ultrasmall AuNPs is summarized and discussed.Finally,we summarize this review and provide some perspective on the future research direction of the ultrasmall AuNPs,aiming to accelerate their clinical translation.
基金financially supported by the National Natural Science Foundation of China(41872046)Doctoral Research Startup Project in 2017 of Guizhou Normal University in ChinaProject of Science and Technology Supporting Plan,Guizhou Province(Qian Sci.Co.[2017],No.2580)。
文摘Sorption between nanoparticles(NPs)and minerals may critically affect the migration of associated elements as well as the environmental impact of NPs.Since illite is widely present in soil,sediment,and water,we have experimentally investigated the sorption behavior of citrate-coated gold nanoparticles(AuNPs)as model NPs on illite under different pH and mineral mass conditions.We demonstrated that sorption of these negatively charged AuNPs strongly depended on the suspension pH.At pH above 8,which coincided with the apparent point of zero charge(pH 7.9)of our illite sample,only marginal sorption of AuNPs was observed.At pH 3-8,significant sorption of AuNPs on illite was found,with almost complete sorption occurring at more acidic conditions(pH 3-4).TEM observations revealed that sorption took place through the attachment AuNPs on illite edges.At pH 2,AuNPs mostly formed chain-like fused structures and precipitated out of the suspension.Based upon the above pH dependence,residual organic ligand content after sorption,and complementary sorption results with positively charged AuNPs,we conclude that the sorption process is mainly driven by the electrostatic attraction between negatively charged AuNPs and positively charged illite edges,with possible competitive involvement of citrate molecules.We expect that our findings will improve our understanding of NP-mineral interaction and the environmental fate of NPs.
文摘With the support of the National Natural Science Foundation of China,Prof.Zhang Tao(张涛)and Prof.Wang Junhu’s group at the Laboratory of Catalysts and New Materials for Aerospace,Dalian Institute of Chemical Physics,Chinese Academy of Sciences,recently discovered a new type of strong metalsupport interaction(SMSI)between gold nanoparticles(NPs)and nonoxides,which was published in
基金The Ministry of Science and Technology of China，the National Natural Science Foundation of China，the Shanghai Rising-Star Program (No.13QA1400600) are acknowledged for their financial supports
文摘Fluorous gold nanoparticle （Fluo-NP）, i.e. gold nanoparticle covered by fluorous ponytail （C8F17-） was pre- pared and found to self-assemble into supra-structures covered by carbohydrates （named supraF-NP）, due to the strong fluorous interaction. More importantly, the re-dispersed supraF-NP （diameter around 200 nm） in water pro- vided an alternative strategy to detect carbohydrate-protein interaction in solution by naked eve.
基金Project (2010-0021425) supported by Basic Science Research Program through a National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science, and Technology, Koreathe support from LG Yonam Foundation
文摘Au/CdTe nanocomposites were prepared by electrostatic interaction between oppositely-charged gold （Au） and cadmium telluride （CdTe） nanoparticles. Au and CdTe nanoparticles were stabilized by 4-（dimethylamino）pyridine （DMAP） and 3-mercaptopropionic acid to develop positive and negative charges on their surfaces in aqueous solutions, respectively. The red shifts of the surface plasmon absorptions with the increase of Au content indicate that the sizes of the nanocomposites expanded due to the complex formation. Mixing ratio of Au and CdTe nanoparticles controls the structure of the resulting composites effectively. Moreover, the sizes and shapes of the mixed nanoparticles are important parameters for the formation of metal/semiconductor nanocomposites. The Au/CdTe nanocomposites were characterized by small angle X-ray scattering technique （SAXS）, transmission electron microscopy （TEM）, cyclic voltammetry （CV） and X-ray photoelectron spectroscopy （XPS）.
基金The National Natural Science Foundation of China(Grant No.81202469)Founder of new drug research fund(Grant No.20130527)
文摘Large Hollow nanoparticulate aggregates（LHNAs） based on albumin nanoparticles is a promising technology for developing dry powder inhaler（DPI） with good aerodynamic properties in order to provide a new drug delivery system（DDS） for the treatment of lung disease. Improved understanding of molecular interactions could lead to prepare the DDS rationally. Therefore, this investigation utilized computations and experiments to reveal the mechanisms of budesonide（BUD） interactions with bovine serum albumin（BSA） at the molecular level. The molecular dynamics（MD） simulation revealed that there were three critical stable binding sites of BUD on BSA（P1, P2, P3） mainly by hydrophobic interaction and hydrogen bond. The energy decomposition of each residue to the whole BUD-BSA complex system in P1-P3 showed that nonpolar residues in or around the binding site played an important role in the binding of BUD to BSA. The molar ratio was close to 3 in preparations in drug-loading efficiency experiment, which was confirmed to the simulation results. The details of the binding sites from computation provided a guideline for the design of the BSA nanoparticles carrying BUD, which was prepared successfully at last. Combination of the MD simulation and experiment as well as the mechanism of the molecular interaction provided a solid theoretical basis for the preparation of BSA-LHNAs for DPI in the future.
基金Financial support from the State General Administration of the People’s Republic of China for Quality Supervision and Inspection and Quarantine(No.2016QK122)the Science and Technology Projects of Jiangxi Province(No.20181BBH80007)+1 种基金Shanghai Institute of Quality Inspection and Technical Researchthe Department of Chemistry,Fudan University。
文摘A convenient colorimetric approach for visual detection of melamine in raw milk was realized by using gold nanoparticles(AuNPs)stabilized by an unsymmetrical terpyridyl zinc complex with a thymine fragment at one terminal and a quaternary ammonium salt at the other.Even without pre-addition of melamine or relative additives,obvious color change from red to blue was observed by naked eye in the presence of trace amount of melamine,which was attributed to the alternation of aggregation state of AuNPs caused by the selective binding between the thymine fragment and melamine via triple hydrogenbonding interactions.Remarkably,the detection limit for melamine was as low as 2.4 ppb,providing a highly sensitive and efficient approach for the visual detection of melamine.
基金the National Natural Science Foundation of China (Nos. 82172372 and 21904045)COVID-19 Pneumonia Emergency Scientific Research Special Fund of Wuhan (No. EX20D03)the Fundamental Research Funds for the Central Universities (Nos. 2019kfy XJJS169 and 2021yjs CXCY127)。
文摘DNA-functionalized gold nanoparticles are one of the most versatile bionanomaterials for biomedical and clinical diagnosis. Herein, we discovered that the performance of DNAzyme cleaving the substrate is highly related to its length. This intriguing phenomenon only appears at the interfaces of DNAfunctionalized gold nanoparticles. We systematically investigated the causes of this phenomenon. We conjectured that the DNAzyme with extended nucleotides that do not match its substrate strand is vulnerable to non-specific adsorption, electrostatic repulsion, and steric hindrance. Based on our improved understanding of this phenomenon, we have successfully developed a highly sensitive and specific amplifiable biosensor to detect human apurinic/apyrimidinic endonuclease 1.
基金financially supported by the National Natural Science Foundation of China(No.21807083)the Program for Innovative Teams of Outstanding Young and Middleaged Researchers in the Higher Education Institutions of Hubei Province(No.T201702)。
文摘Based on the host-guest molecular recognition capability of cucurbit[6]uril(CB[6])modified on the gold surface,sensitive spectrophotometric and electrochemical methods for the detection of metformin(MET)have been developed.The molecular recognition between cucurbit[7]uril(CB[7])or CB[6]and MET is initially demonstrated and the related recognition mechanism is further deliberated.First,CB[6]-modified gold nanoparticles(AuNPs/CB[6])were synthesized and then characterized by ultraviolet visible light spectrum(UV–vis)and transmission electron microscopy(TEM).The aggregation of Au NPs/CB[6]prompted by MET triggered changes of color and the absorption spectrum,that explored for the visual identification and spectrophotometric determination of MET.Under the optimized detection conditions,the UV–vis spectrometry had a good linear relationship in the range of 6–700μmol/L,and the detection limit was 2μmol/L.In addition,a single-layer CB[6]-modified gold electrode(GE-CB[6])detection system for MET was constructed.As the concentration of MET in the solution continues to increase,the charge transfer resistance(Rct)in the Nyquist diagram of the electrochemical impedance method(EIS)continues to increase.In the concentration range from 10 pmol/L to 20 nmol/L,the logarithm of the MET concentration has a good linear relationship with Rct,and the detection limit of this method is 1.35 pmol/L.Both methods have good concentration sensitivity to MET in different concentration ranges,providing a powerful tool for the detection of MET.
基金financially supported by the National Natural Science Foundation of China(No.20975067)RFDP (No.20090073120039)Shanghai Educational Development Foundation(No.2008CG12)
文摘Gold nanoparticles （GNPs） have been widely used as probes and nanomaterials in certain biological and biomedical fields thanks to its special physical and chemical properties. However, it is still difficult to characterize GNPs-bioconjugates in solution, which has greatly limited further bioapplications of GNPs. In this study, we reported a single particle method for characterizing GNPs- biomolecules in solution using resonance light scattering correlation spectroscopy （RLSCS）. The interaction of GNPs with bovine serum albumin （BSA） and thiol-modified oligonucletides were investigated.
文摘Covalent organic frameworks(COFs)have lately emerged as a blooming class of potential materials for photocatalytic water splitting because of their high crystallinity,huge surface areas,and structural versatility.However,the photocatalytic performance for most pure COFs face some limitations factors,such as the significant recombination of photogenerated carriers and slow charge transfer.Herein,a novel thioether-functionalized pyrene-based COF(S_(4)-COF)was effectively produced and chosen as a support for the immobilization of ultrafine gold nanoparticles(Au NPs).S_(4)-COF photocatalyst with Au as cocatalyst demonstrates remarkable photocatalytic activity with a H_(2) generation rate of 1377μmol g^(−1) h^(−1) under visible light(>420 nm),which is ca.4.5-fold increase comparing to that of pure S_(4)-COF(302μmol g^(−1) h^(−1)).Au NPs anchored on S_(4)-COF possess an ultrafine size distribution ranging from 1.75 to 6.25 nm with an average size centered at 3.8 nm,which benefits from the coordination interaction between thioether groups and Au.Meanwhile,the produced Au@S_(4)-COF can generate a stable photocatalytic H_(2) generation during the four recycles and preserve its crystallinity structure after the stability testing.The Au NPs anchored on the S_(4)-COF photocatalyst can greatly accelerate the separation of photogenerated carriers and increase charge transfer because of the combined function of Au NPs and thioether groups.Such a method can not only prevent the aggregation of Au NPs onto thioether-containing COFs to achieve long-term photostability but also allow uniform dispersion for an ordered structure of photocatalysts.This work provides a rational strategy for designing and preparing COF-based photocatalysts for solar-driven H_(2) production.
文摘An indirect immunoassay for detecting antigen was developed. It was based on fluorescence resonance energy transfer (FRET) and quenching of gold nanoparticles. Bovine serum albumin (BSA) was chosen as model antigen. Fluorescein isothiocyanate (FITC) was attached to anti-BSA antibody (anti-BSA–FITC) as FRET donor, while BSA was conjugated to gold nanoparticles (GNPs–BSA) as FRET acceptor. The formation of anti-BSA–BSA immunocomplex resulted in the FRET between anti-BSA–FITC and GNPs–BSA. Thus, the fluorescence of FRET donor was quenched, and the decreasing fluorescence intensity responded linearly to the concentration of acceptor within the linear range. The concentration of BSA we obtained according to the stoichiometric ratio between BSA and GNPs. Following this approach, we were able to specifically detect BSA. The detection limit for BSA was 0.5 nM and the linear range of the assay was 2.9 - 43.5 nM. It had been successfully applied to specific detection of BSA in serum samples.
