Characterizing and control the chemical compositions of multi-element particles as single metal nanoparticles(mNPs) on the surfaces of catalytic metal oxide supports is challenging.This can be attributed to the hetero...Characterizing and control the chemical compositions of multi-element particles as single metal nanoparticles(mNPs) on the surfaces of catalytic metal oxide supports is challenging.This can be attributed to the heterogeneity and large size at the nanoscale,the poorly defined catalyst nanostructure,and thermodynamic immiscibility of the strongly repelling metallic elements.To address these challenges,an ultrasonic-assisted coincident electro-oxidation-reduction-precipitation(U-SEO-P) is presented to fabricate ultra-stable PtRuAgCoCuP NPs,which produces numerous active intermediates and induces strong metal-support interactions.To sort the active high-entropy mNPs,individual NPs are described on the support surface and the role of deep learning in understanding/predicting the features of PtRuAgCoCu@TiO_(x) catalysts is explained.Notably,this deep learning approach required minimal to no human input.The as-prepared PtRuAgCoCu@TiO_(x) catalysts can be used to catalyze various important chemical reactions,such as a high reduction conversion(100% in 30 s),with no loss of catalytic activity even after 20 cycles of nitroarene and ketone/aldehyde,which is several times higher than commercial Pt@TiO_(x) owing to individual PtRuAgCoCuP NPs on TiO_(x) surface.In this study,we present the "Totally Defined Catalysis" concept,which has enormous potential for the advancement of high-activity catalysts in the reduction of organic compounds.展开更多
Nanomaterials are materials in which at least one of the dimensions of the particles is 100 nm and below.There are many types of nanomaterials,but noble metal nanoparticles are of interest due to their uniquely large ...Nanomaterials are materials in which at least one of the dimensions of the particles is 100 nm and below.There are many types of nanomaterials,but noble metal nanoparticles are of interest due to their uniquely large surface-to-volume ratio,high surface area,optical and electronic properties,high stability,easy synthesis,and tunable surface functionalization.More importantly,noble metal nanoparticles are known to have excellent compatibility with bio-materials,which is why they are widely used in biological applications.The synthesis method of noble metal nanoparticles conventionally involves the reduction of the noble metal salt precursor by toxic reaction agents such as NaBH4,hydrazine,and formaldehyde.This is a major drawback for researchers involved in biological application researches.Hence,the bio-synthesis of noble metal nanoparticles(NPs)by bio-materials via bio-reduction provides an alternative method to synthesize noble metal nanoparticles which are potentially non-toxic and safer for biological application.In this review,the bio-synthesis of noble metal nanoparticle including gold nanoparticle(AuNPs),silver nanoparticle(AgNPs),platinum nanoparticle(PtNPs),and palladium nanoparticle(PdNPs)are first discussed.This is followed by a discussion of these biosynthesized noble metal in biological applications including antimicrobial,wound healing,anticancer drug,and bioimaging.Based on these,it can be concluded that the study on bio-synthesized noble metal nanoparticles will expand further involving bio-reduction by unexplored bio-materials.However,many questions remain on the feasibility of bio-synthesized noble metal nanoparticles to replace existing methods on various biological applications.Nevertheless,the current development of the biological application by bio-synthesized noble metal NPs is still intensively ongoing,and will eventually reach the goal of full commercialization.展开更多
Several PVP-stabilized colloidal platinum metals nanoparticles have been synthesized and characterized by FTIR and TEM.Comparing with the pure PVP,carbonyl groups of PVP in the mixture of PVP and the metal precursors ...Several PVP-stabilized colloidal platinum metals nanoparticles have been synthesized and characterized by FTIR and TEM.Comparing with the pure PVP,carbonyl groups of PVP in the mixture of PVP and the metal precursors or in the PVP-stabilized metal nanoparticles have obvious peak shifts in FTIR spectra.The peak shifts reveal the interaction between PVP and the metal species.The interaction between PVP and metal precursors has effect on the formation of the colloidal metal nanoparticles.Strength of the intera...展开更多
The near-field and far-field second harmonic (SH) responses of a metal spherical nanoparticle placed in the focal region of a highly focused beam are investigated by using the calculation model based on three-dimens...The near-field and far-field second harmonic (SH) responses of a metal spherical nanoparticle placed in the focal region of a highly focused beam are investigated by using the calculation model based on three-dimensional finite-difference time-domain (FDTD) method. The results show that off-axis backward-propagating SH response can be reinforced by tightly focusing, due to the increase of the relative magnitude of the longitudinal field component and the phase shift along the propagation direction.展开更多
The n-type semiconducting titanium oxide thin films are well-known as electron transporting interlayer in photovoltaic cells. The favorable characteristics of interlayers in photovoltaics are high optical transmittan...The n-type semiconducting titanium oxide thin films are well-known as electron transporting interlayer in photovoltaic cells. The favorable characteristics of interlayers in photovoltaics are high optical transmittance (T%), wide band gap energy (Eg) and high electrical conductivity (σ). Modifying titanium oxide films with metal nanoparticles would increase electrical conductivity but reduce optical band gap energy. We developed the sol-gel derived titanium suboxide (TiOx) films modified with silver (Ag) or gold (Au) or copper (Cu) nanoparticles (NPs). This study explores a tradeoff between narrowing optical band gap and enhancing electrical conductivity of nanostructured TiOx films by controlling the Au- or Ag- or Cu-NPs loading concentrations (mol%) in titania. The Au- and Cu-NPs loading concentration of 4 mol% should meet a tradeoff which yields the higher T%, wider Eg and higher compared to those of pure TiOx films. In addition, since the pure Cu is not thermodynamically stable in ambience as compared to Au and Ag, the stability of as-obtained colloidal CuNPs is also examined. A careful examination of the time evolution of surface plasmon resonance (SPR) bands of CuNPs indicates that their stability is only up to 4 h.展开更多
Catalytic properties of polymer-stabilized colloidal metal nanoparticles synthesized by microwave irradiationwere studied in the selective hydrogenation of unsaturated aldehydes,o-chloronitrobenzene and the hydrogenat...Catalytic properties of polymer-stabilized colloidal metal nanoparticles synthesized by microwave irradiationwere studied in the selective hydrogenation of unsaturated aldehydes,o-chloronitrobenzene and the hydrogenationof alkenes.The results show that nanosized metal particles synthesized by microwave irradiation have similar catalyticperformance in selective hydrogenation of unsaturated aldehydes,better selectivity to o-chloroaniline in hydrogenation ofo-chloronitrobenzene and higher catalytic activities in hydrogenation of alkenes,compared with metal clusters prepared byconventional heating.The same apparent activation energy(E_a=29 kJ mol^(-(?)) for hydrogenation of (?)-heptene catalyzed withplatinum nanoparticles prepared by both heating modes implied that the reaction followed the same mechanism.展开更多
Abnormal melting point depression of metal nanoparticles often occurs in heterogeneous catalytic reactions,which leads to a reduction in the stability of reactive nanoclusters.To study this abnormal phenomenon,the ori...Abnormal melting point depression of metal nanoparticles often occurs in heterogeneous catalytic reactions,which leads to a reduction in the stability of reactive nanoclusters.To study this abnormal phenomenon,the original and surface-energy modified Gibbs-Thomson equations were analyzed in this work and further modified by considering the effect of the substrate.The results revealed that the original Gibbs-Thomson equation was not suitable for the particles with radii smaller than 10 nm.Moreover,the performance of the surface-energy modified Gibbs-Thomson equation was improved,and the deviation was reduced to(-350-100)K,although further modification of the equation by considering the interfacial effect was necessary for the small particles(r<5 nm).The new model with the interfacial effect improved the model performance with a deviation of approximately-50 to 20 K,where the interfacial effect can be predicted quantitatively from the thermodynamic properties of the metal and substrate.Additionally,the micro-wetting parameterα_W can be used to qualitatively study the overall impact of the substrate on the melting point depression.展开更多
Cancer,a complex and heterogeneous disease,arises from genomic instability.Currently,DNA damage-based cancer treatments,including radiotherapy and chemotherapy,are employed in clinical practice.However,the efficacy an...Cancer,a complex and heterogeneous disease,arises from genomic instability.Currently,DNA damage-based cancer treatments,including radiotherapy and chemotherapy,are employed in clinical practice.However,the efficacy and safety of these therapies are constrained by various factors,limiting their ability to meet current clinical demands.Metal nanoparticles present promising avenues for enhancing each critical aspect of DNA damage-based cancer therapy.Their customizable physicochemical properties enable the development of targeted and personalized treatment platforms.In this review,we delve into the design principles and optimization strategies of metal nanoparticles.We shed light on the limitations of DNA damage-based therapy while highlighting the diverse strategies made possible by metal nanoparticles.These encompass targeted drug delivery,inhibition of DNA repair mechanisms,induction of cell death,and the cascading immune response.Moreover,we explore the pivotal role of physicochemical factors such as nanoparticle size,stimuli-responsiveness,and surface modification in shaping metal nanoparticle platforms.Finally,we present insights into the challenges and future directions of metal nanoparticles in advancing DNA damage-based cancer therapy,paving the way for novel treatment paradigms.展开更多
The low signal-to-noise ratio(S/N)and single functionality of fluorescence imaging agents have limited their practical applications.Bright two-photon excitation(2PE)imaging probes are highly desirable in vivo with lar...The low signal-to-noise ratio(S/N)and single functionality of fluorescence imaging agents have limited their practical applications.Bright two-photon excitation(2PE)imaging probes are highly desirable in vivo with larger imaging depth,minor autofluorescence background,and less photodamage.Herein,we developed responsive aggregated gold nanoparticles(Au NPs)as high contrast 2PE imaging agents,capable of emitting red fluorescence upon excitation of near-infrared(NIR)laser and possessing a high signal-to-noise ratio(S/N of 2,475).By forming aggregates in situ inside tumor tissue,doxorubicin hydrochloride(DOX)-loaded mix-charged gold nanoparticles(DOX-MC-Au NPs)were utilized to act as selective fluorescence imaging probes and precise therapy agents.These high-contrast theranostic agents offer a promising potential for precise cancer imaging and therapy,which might open a new venue to multifunctional and noninvasive theranostics.展开更多
Prevention of spreading viral respiratory disease,especially in case of a pandemic such as coronavirus disease of 2019(COVID-19),has been proved impossible without considering obligatory face mask-wearing protocols fo...Prevention of spreading viral respiratory disease,especially in case of a pandemic such as coronavirus disease of 2019(COVID-19),has been proved impossible without considering obligatory face mask-wearing protocols for both healthy and contaminated populations.The widespread application of face masks for long hours and almost everywhere increases the risks of bacterial growth in the warm and humid environment inside the mask.On the other hand,in the absence of antiviral agents on the surface of the mask,the virus may have a chance to stay alive and be carried to different places or even put the wearers at risk of contamination when touching or disposing the masks.In this article,the antiviral activity and mechanism of action of some of the potent metal and metal oxide nanoparticles in the role of promising virucidal agents have been reviewed,and incorporation of them in an electrospun nanofibrous structure has been considered an applicable method for the fabrication of innovative respiratory protecting materials with upgraded safety levels.展开更多
Through partial deligandation of metal-organic frameworks(MOFs),quasi-MOFs with a transition structure between MOFs and metal compounds(such as metal oxides,nitrides,sulfides,and phosphides)can be fabricated.Quasi-MOF...Through partial deligandation of metal-organic frameworks(MOFs),quasi-MOFs with a transition structure between MOFs and metal compounds(such as metal oxides,nitrides,sulfides,and phosphides)can be fabricated.Quasi-MOFs can not only retain the porous structure of MOFs to a certain extent,but also expose the inorganic nodes to the guest species(e.g.,metal nanoparticles)to show enhanced metal-support interaction for synergistic catalysis.This concept was first demonstrated by our group through calcining Au/MIL-101 at different temperatures under Ar flow to adjust the interface between Au nanoparticles and the inorganic Cr–O nodes.The obtained Au/quasi-MIL-101 showed superior enhanced catalytic activity in the oxidation of carbon monoxide.This study has inspired further research interest to fabricate other quasi-MOFs through controlled deligandation of mono-and bimetallic MOFs and their composites for the design of efficient catalysts.展开更多
While metal nanoparticles(NPs)have shown great promising applications as heterogeneous catalysts,their agglomeration caused by thermodynamic instability is detrimental to the catalytic performance.To tackle this hurdl...While metal nanoparticles(NPs)have shown great promising applications as heterogeneous catalysts,their agglomeration caused by thermodynamic instability is detrimental to the catalytic performance.To tackle this hurdle,we successfully prepared a functional and stable porphyrinic metal-organic framework(MOF),PCN-224-RT,as a host for encapsulating metal nanoparticles by direct stirring at room temperature.As a result,Pt@PCN-224-RT composites with well-dispersed Pt NPs can be constructed by introducing pre-synthesized Pt NPs into the precursor solution of PCN-224-RT.Of note,the rapid and simple stirring method in this work is more in line with the requirements of environmental friendly and industrialization compared with traditional solvothermal methods.展开更多
This review summarizes the utilization of supported noble metal nanoparticles (such as Au/TiO2, Au/ZrO2, Ag/AgCl) as efficient photo/sono-catalysts for the selective synthesis of chemicals and degradation of environme...This review summarizes the utilization of supported noble metal nanoparticles (such as Au/TiO2, Au/ZrO2, Ag/AgCl) as efficient photo/sono-catalysts for the selective synthesis of chemicals and degradation of environmental pollutants. Supported noble metal nanoparticles could efficiently catalyze the conversion of solar energy into chemical energy. Under UV/visible light irradiation, important chemical transformations such as the oxidation of alcohols to carbonyl compounds, the oxidation of thiol to disulfide, the oxidation of benzene to phenol, and the reduction of nitroaromatic compounds to form aromatic azo compounds, are effectively achieved by supported noble metal nanoparticles. Under ultrasound irradiation, supported noble metal nanoparticles could efficiently catalyze the production of hydrogen from water. Moreover, various pollutants, including aldehydes, alcohols, acids, phenolic compounds, and dyes, can be effectively decomposed over supported noble metal nanoparticles under UV/visible light irradiation. Under ultrasound irradiation, pollutant molecules can also be completely degraded with supported noble metal nanoparticles as catalysts.展开更多
Herein, we report a plasmonic metal nanoparti- cle-involved sensor for cyanide ion based on the inner filter effect by using photoluminescent carbon dots as the signal reporter. With commercial bee pollen as the carbo...Herein, we report a plasmonic metal nanoparti- cle-involved sensor for cyanide ion based on the inner filter effect by using photoluminescent carbon dots as the signal reporter. With commercial bee pollen as the carbon resource, we synthesized photoluminescent nitrogen-doped carbon dots by a one-pot hydrothermal process, and their fluores- cence quantum yield reached as high as 10.2 % ± 0.5 %. Fluorescence measurements indicated that the fluorescence of the carbon dots was insusceptible to the presence of many environmentally ordinary ions. Thanks to this “inert” property, we then developed a turn-on fluorescent sensor for cyanide ion in an inner filter effect manner by using carbon dots as the fluorophore and gold or silver nanoparticle as the light absorber. This detection technique is expected to be used for other metal nanoparticles-carbon dots ensemble fluorescent assays.展开更多
We use the method of discrete dipole approximation with surface interaction to construct a model in which a plurality of nanoparticles is arranged on the surface of BK7 glass. Nanoparticles are in air medium illuminat...We use the method of discrete dipole approximation with surface interaction to construct a model in which a plurality of nanoparticles is arranged on the surface of BK7 glass. Nanoparticles are in air medium illuminated by evanescent wave generated from total internal reflection. The effects of the wavelength, the polarization of the incident wave, the number of nanoparticles and the spacing of multiple nanoparticles on the field enhancement and extinction efficiency are calculated by our model. Our work could pave the way to improve the field enhancement of multiple nanoparticles systems.展开更多
The realization of plasmonic structures generally necessitates expensive fabrication techniques, such as electron beam and focused ion beam lithography, allowing for the top-down fabrication of low-dimensional structu...The realization of plasmonic structures generally necessitates expensive fabrication techniques, such as electron beam and focused ion beam lithography, allowing for the top-down fabrication of low-dimensional structures. Another approach to make plasmonic structures in a bottom-up fashion is colloidal synthesis, which is convenient for liquid-state applications or very thin solid films where aggregation problems are an important challenge. The architectures prepared using these methods are typically not robust enough for easy handling and convenient integration. Therefore, developing a new plasmonic robust platform having large-scale dimensions without adversely affecting the plasmonic features is in high demand. As a solution, here we present a new plasmonic composite structure consisting of gold nanoparticles (Au NPs) incorporated into sucrose macrocrystals on a large scale, while preserving the plasmonic nature of the Au NPs and providing robustness in handling at the same time. As a proof of concept demonstration, we present the fluorescence enhancement of green CdTe quantum dots (QDs) via plasmonic coupling with these Au NPs in the sucrose crystals. The obtained composite material exhibits centimeter scale dimensions and the resulting quantum efficiency (QE) is enhanced via the interplay between the Au NPs and CdTe QDs by 58% (from 24% to 38%). Moreover, a shortening in the photoluminescence lifetime from 11.0 to 7.40 ns, which corresponds to a field enhancement factor of 2.4, is observed upon the introduction of Au NPs into the QD incorporated macrocrystals. These results suggest that such "sweet" plasmonic crystals are promising for large-scale robust platforms to embed plasmonic nanoparticles.展开更多
Fabrication of multifunctional catalysts has always been the pursuit of synthetic chemists due to their efficiency,cost-effectiveness,and environmental friendliness.However,it is difficult to control multi-step reacti...Fabrication of multifunctional catalysts has always been the pursuit of synthetic chemists due to their efficiency,cost-effectiveness,and environmental friendliness.However,it is difficult to control multi-step reactions in one-pot,especially the spatial compartmentalization of incompatible active sites.Herein,we constructed metal-organic framework(MOF)composites which regulate the location distribution of metal nanoparticles according to the reaction path and coupled with the diffusion of substrates to achieve tandem reaction.The designed UiO-66-Pt-Au catalyst showed good activity and selectivity in hydrosilylation-hydrogenation tandem reaction,because the uniform microporous structures can control the diffusion path of reactants and intermediates,and Pt and Au nanoparticles were arranged in core-shell spatial distribution in UiO-66.By contrast,the low selectivity of catalysts with random deposition and physical mixture demonstrated the significance of artificial control to the spatial compartmentalization of active sites in tandem catalytic reactions,which provides a powerful approach for designing high-performance and multifunctional heterogeneous catalysts.展开更多
In this study, stabilized Pd, Pt and Au nanoparticles were successfully prepared in aqueous phase using sodium carboxymethyl cellulose (CMC) as a capping agent. These metal nanoparticles were then tested for catalyt...In this study, stabilized Pd, Pt and Au nanoparticles were successfully prepared in aqueous phase using sodium carboxymethyl cellulose (CMC) as a capping agent. These metal nanoparticles were then tested for catalytic hydrodechlorination toward two classes of organochlorinated compounds (vinyl polychlorides includ- ing trichloroethylene (TCE), tetrachloroethylene (PCE), and alkyl polychlorides including 1,1,1-trichloroethane (1,1,1-TCA), and 1,1,1,2-tetrachloroethane (1,1,1,2- TeCA)) to determine the rate-limiting steps and to explore the reaction mechanisms. The surface area normalized reaction rate constant, ksA, showed a systematic depen- dence on the electronic structure (the density of states at the Fermi level) of the metals, suggesting that adsorption of organochlorinated reactants on the metal catalyst surfaces is the rate-limiting step for catalytic hydrodechlorination. Hydrodechlorination rates of 1,1,1-TCA and 1,1,1,2-TeCA agreed with the bond strength of the first (weakest) dissociated C-C1 bond, suggesting that C-C1 bond cleavage, which is the first step for dissociative adsorption of the alkyl polychlorides, controlled the catalytic hydro- dechlorination rate. However, hydrodechlorination rates of TCE and PCE correlated with the adsorption energies of their molecular (non-dissociative) adsorption on the noble metals rather than with the first C-C1 bond strength, suggesting that molecular adsorption governs the reaction rate for hydrodechlorination of the vinyl polychlorides.展开更多
Photothermal therapy is emerging as a very promising way for minimally invasive cancer treatment.To enhance thermal energy deposition of laser in target malignant tissues,liquid metal nanoparticles(LMNPs)have been rec...Photothermal therapy is emerging as a very promising way for minimally invasive cancer treatment.To enhance thermal energy deposition of laser in target malignant tissues,liquid metal nanoparticles(LMNPs)have been recently identified as completely unprecedented photothermal sensitizers due to their unique physicochemical properties and superior photothermal conversion rate under near-infrared(NIR)laser irradiation.However,there is currently a strong lack of understanding of the laser energy distribution and the transient temperature field within the biological tissues,which would seriously hinder the development of LMNPs assisted photothermal therapy.Therefore,this paper focused on the distinctive photothermal effect of LMNPs embedded in biological tissues under NIR laser irradiation.The mathematical model coupling the Monte-Carlo photon transport model with Penne's bioheat transfer model has been established.Simulation studies have shown that LMNPs play an important role in enhancing the absorption of NIR laser,which contributes to local temperature rise and improves the temperature distribution.Comparing with the control case without LMNPs,the maximum temperature increases by nearly 1.0 time,the local temperature rise reaches 30℃ in 1.0 second.When the diameter and concentration of LMNPs are 40 nm and 1012/mm3,the resulting temperature variation and distribution is best for the effective killing of tumors without damaging normal tissues.In addition,the simulation results are meaningful for guiding the selection of laser irradiation time in conjunction with the cooling time,ensuring the controllable accuracy of treatment.To the best of our knowledge,the present study is one of the first attempts to quantify the influence of transformable LMNPs on the temperature distributions inside the biological tissues,showing important academic significance for guiding LMNPs assisted photothermal treatment.展开更多
Oxidative dehydrogenation of propane with carbon dioxide(CO_(2)-ODP)characterizes the tandem dehydrogenation of propane to propylene with the reduction of the greenhouse gas of CO_(2)to valuable CO.However,the existin...Oxidative dehydrogenation of propane with carbon dioxide(CO_(2)-ODP)characterizes the tandem dehydrogenation of propane to propylene with the reduction of the greenhouse gas of CO_(2)to valuable CO.However,the existing catalyst is limited due to the poor activity and stability,which hinders its industrialization.Herein,we design the finned Zn-MFI zeolite encapsulated noble metal nanoparticles(NPs)as bifunctional catalysts(NPs@Zn-MFI)for CO_(2)-ODP.Characterization results reveal that the Zn2+species are coordinated with the MFI zeolite matrix as isolated cations and the NPs of Pt,Rh,or Rh Pt are highly dispersed in the zeolite crystals.The isolated Zn2+cations are very effective for activating the propane and the small NPs are favorable for activating the CO_(2),which synergistically promote the selective transformation of propane and CO_(2)to propylene and CO.As a result,the optimal 0.25%Rh0.50%Pt@Zn-MFI catalyst shows the best propylene yield,satisfactory CO_(2)conversion,and long-term stability.Moreover,considering the tunable synergetic effects between the isolated cations and NPs,the developed approach offers a general guideline to design more efficient CO_(2)-ODP catalysts,which is validated by the improved performance of the bifunctional catalysts via simply substituting Sn4+cations for Zn2+cations in the MFI zeolite matrix.展开更多
基金National Research Foundation (NRF) of South Korea (NRF-2022R1A2C1004392)Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education (IRIS RS-202300240109)。
文摘Characterizing and control the chemical compositions of multi-element particles as single metal nanoparticles(mNPs) on the surfaces of catalytic metal oxide supports is challenging.This can be attributed to the heterogeneity and large size at the nanoscale,the poorly defined catalyst nanostructure,and thermodynamic immiscibility of the strongly repelling metallic elements.To address these challenges,an ultrasonic-assisted coincident electro-oxidation-reduction-precipitation(U-SEO-P) is presented to fabricate ultra-stable PtRuAgCoCuP NPs,which produces numerous active intermediates and induces strong metal-support interactions.To sort the active high-entropy mNPs,individual NPs are described on the support surface and the role of deep learning in understanding/predicting the features of PtRuAgCoCu@TiO_(x) catalysts is explained.Notably,this deep learning approach required minimal to no human input.The as-prepared PtRuAgCoCu@TiO_(x) catalysts can be used to catalyze various important chemical reactions,such as a high reduction conversion(100% in 30 s),with no loss of catalytic activity even after 20 cycles of nitroarene and ketone/aldehyde,which is several times higher than commercial Pt@TiO_(x) owing to individual PtRuAgCoCuP NPs on TiO_(x) surface.In this study,we present the "Totally Defined Catalysis" concept,which has enormous potential for the advancement of high-activity catalysts in the reduction of organic compounds.
基金This work was financially supported by the National Natural Science Foundation of China(No.21536010).
文摘Nanomaterials are materials in which at least one of the dimensions of the particles is 100 nm and below.There are many types of nanomaterials,but noble metal nanoparticles are of interest due to their uniquely large surface-to-volume ratio,high surface area,optical and electronic properties,high stability,easy synthesis,and tunable surface functionalization.More importantly,noble metal nanoparticles are known to have excellent compatibility with bio-materials,which is why they are widely used in biological applications.The synthesis method of noble metal nanoparticles conventionally involves the reduction of the noble metal salt precursor by toxic reaction agents such as NaBH4,hydrazine,and formaldehyde.This is a major drawback for researchers involved in biological application researches.Hence,the bio-synthesis of noble metal nanoparticles(NPs)by bio-materials via bio-reduction provides an alternative method to synthesize noble metal nanoparticles which are potentially non-toxic and safer for biological application.In this review,the bio-synthesis of noble metal nanoparticle including gold nanoparticle(AuNPs),silver nanoparticle(AgNPs),platinum nanoparticle(PtNPs),and palladium nanoparticle(PdNPs)are first discussed.This is followed by a discussion of these biosynthesized noble metal in biological applications including antimicrobial,wound healing,anticancer drug,and bioimaging.Based on these,it can be concluded that the study on bio-synthesized noble metal nanoparticles will expand further involving bio-reduction by unexplored bio-materials.However,many questions remain on the feasibility of bio-synthesized noble metal nanoparticles to replace existing methods on various biological applications.Nevertheless,the current development of the biological application by bio-synthesized noble metal NPs is still intensively ongoing,and will eventually reach the goal of full commercialization.
基金This work was financially supported by the SRF for ROCS,SEM.(No. LX2005-03)Sponsored by CNPC Innovation Fund(No.05E7002).
文摘Several PVP-stabilized colloidal platinum metals nanoparticles have been synthesized and characterized by FTIR and TEM.Comparing with the pure PVP,carbonyl groups of PVP in the mixture of PVP and the metal precursors or in the PVP-stabilized metal nanoparticles have obvious peak shifts in FTIR spectra.The peak shifts reveal the interaction between PVP and the metal species.The interaction between PVP and metal precursors has effect on the formation of the colloidal metal nanoparticles.Strength of the intera...
基金Project supported by the National Natural Science Foundation of China(Grant No.61378005)
文摘The near-field and far-field second harmonic (SH) responses of a metal spherical nanoparticle placed in the focal region of a highly focused beam are investigated by using the calculation model based on three-dimensional finite-difference time-domain (FDTD) method. The results show that off-axis backward-propagating SH response can be reinforced by tightly focusing, due to the increase of the relative magnitude of the longitudinal field component and the phase shift along the propagation direction.
文摘The n-type semiconducting titanium oxide thin films are well-known as electron transporting interlayer in photovoltaic cells. The favorable characteristics of interlayers in photovoltaics are high optical transmittance (T%), wide band gap energy (Eg) and high electrical conductivity (σ). Modifying titanium oxide films with metal nanoparticles would increase electrical conductivity but reduce optical band gap energy. We developed the sol-gel derived titanium suboxide (TiOx) films modified with silver (Ag) or gold (Au) or copper (Cu) nanoparticles (NPs). This study explores a tradeoff between narrowing optical band gap and enhancing electrical conductivity of nanostructured TiOx films by controlling the Au- or Ag- or Cu-NPs loading concentrations (mol%) in titania. The Au- and Cu-NPs loading concentration of 4 mol% should meet a tradeoff which yields the higher T%, wider Eg and higher compared to those of pure TiOx films. In addition, since the pure Cu is not thermodynamically stable in ambience as compared to Au and Ag, the stability of as-obtained colloidal CuNPs is also examined. A careful examination of the time evolution of surface plasmon resonance (SPR) bands of CuNPs indicates that their stability is only up to 4 h.
基金The Project is partially supported by the Natural Science Foundation of Hubei Province(Contract No.2003ABA072).
文摘Catalytic properties of polymer-stabilized colloidal metal nanoparticles synthesized by microwave irradiationwere studied in the selective hydrogenation of unsaturated aldehydes,o-chloronitrobenzene and the hydrogenationof alkenes.The results show that nanosized metal particles synthesized by microwave irradiation have similar catalyticperformance in selective hydrogenation of unsaturated aldehydes,better selectivity to o-chloroaniline in hydrogenation ofo-chloronitrobenzene and higher catalytic activities in hydrogenation of alkenes,compared with metal clusters prepared byconventional heating.The same apparent activation energy(E_a=29 kJ mol^(-(?)) for hydrogenation of (?)-heptene catalyzed withplatinum nanoparticles prepared by both heating modes implied that the reaction followed the same mechanism.
基金Financial supports from Key Project(21838004)Joint Research Fund for Overseas Chinese,Hong Kong,Macao Young Scientists of National Natural Science Foundation(21729601)of China+1 种基金the Swedish Research Councilthe Kempe Foundation for financial support。
文摘Abnormal melting point depression of metal nanoparticles often occurs in heterogeneous catalytic reactions,which leads to a reduction in the stability of reactive nanoclusters.To study this abnormal phenomenon,the original and surface-energy modified Gibbs-Thomson equations were analyzed in this work and further modified by considering the effect of the substrate.The results revealed that the original Gibbs-Thomson equation was not suitable for the particles with radii smaller than 10 nm.Moreover,the performance of the surface-energy modified Gibbs-Thomson equation was improved,and the deviation was reduced to(-350-100)K,although further modification of the equation by considering the interfacial effect was necessary for the small particles(r<5 nm).The new model with the interfacial effect improved the model performance with a deviation of approximately-50 to 20 K,where the interfacial effect can be predicted quantitatively from the thermodynamic properties of the metal and substrate.Additionally,the micro-wetting parameterα_W can be used to qualitatively study the overall impact of the substrate on the melting point depression.
基金funded by National Key Research and Development Program of China(2022YFB3203804,2022YFB3203801,2022YFB3203800)the Leading Talent of“Ten Thousand Plan”National High-Level Talents Special Support Plan,National Natural Science Foundation of China(32071374,32000985)+4 种基金Program of Shanghai Academic Research Leader under the Science and Technology Innovation Action Plan(21XD1422100,China)Program of Shanghai Science and Technology Development(22TS1400700,China)Zhejiang Provincial Natural Science Foundation of China(LR22C100001,LQ21H300003,China)Innovative Research Team of High-Level Local Universities in Shanghai(SHSMU-ZDCX20210900,China)CAS Interdisciplinary Innovation Team(JCTD-2020-08,China)。
文摘Cancer,a complex and heterogeneous disease,arises from genomic instability.Currently,DNA damage-based cancer treatments,including radiotherapy and chemotherapy,are employed in clinical practice.However,the efficacy and safety of these therapies are constrained by various factors,limiting their ability to meet current clinical demands.Metal nanoparticles present promising avenues for enhancing each critical aspect of DNA damage-based cancer therapy.Their customizable physicochemical properties enable the development of targeted and personalized treatment platforms.In this review,we delve into the design principles and optimization strategies of metal nanoparticles.We shed light on the limitations of DNA damage-based therapy while highlighting the diverse strategies made possible by metal nanoparticles.These encompass targeted drug delivery,inhibition of DNA repair mechanisms,induction of cell death,and the cascading immune response.Moreover,we explore the pivotal role of physicochemical factors such as nanoparticle size,stimuli-responsiveness,and surface modification in shaping metal nanoparticle platforms.Finally,we present insights into the challenges and future directions of metal nanoparticles in advancing DNA damage-based cancer therapy,paving the way for novel treatment paradigms.
基金supported by the Science and Technology Project of Jiangsu Province(BZ2022056)the Ministry of Education,Singapore(Tier 1 A-8000013-00-00)。
文摘The low signal-to-noise ratio(S/N)and single functionality of fluorescence imaging agents have limited their practical applications.Bright two-photon excitation(2PE)imaging probes are highly desirable in vivo with larger imaging depth,minor autofluorescence background,and less photodamage.Herein,we developed responsive aggregated gold nanoparticles(Au NPs)as high contrast 2PE imaging agents,capable of emitting red fluorescence upon excitation of near-infrared(NIR)laser and possessing a high signal-to-noise ratio(S/N of 2,475).By forming aggregates in situ inside tumor tissue,doxorubicin hydrochloride(DOX)-loaded mix-charged gold nanoparticles(DOX-MC-Au NPs)were utilized to act as selective fluorescence imaging probes and precise therapy agents.These high-contrast theranostic agents offer a promising potential for precise cancer imaging and therapy,which might open a new venue to multifunctional and noninvasive theranostics.
基金National Institute of Biomedical Imaging and Bioengineering(5T32EB009035).
文摘Prevention of spreading viral respiratory disease,especially in case of a pandemic such as coronavirus disease of 2019(COVID-19),has been proved impossible without considering obligatory face mask-wearing protocols for both healthy and contaminated populations.The widespread application of face masks for long hours and almost everywhere increases the risks of bacterial growth in the warm and humid environment inside the mask.On the other hand,in the absence of antiviral agents on the surface of the mask,the virus may have a chance to stay alive and be carried to different places or even put the wearers at risk of contamination when touching or disposing the masks.In this article,the antiviral activity and mechanism of action of some of the potent metal and metal oxide nanoparticles in the role of promising virucidal agents have been reviewed,and incorporation of them in an electrospun nanofibrous structure has been considered an applicable method for the fabrication of innovative respiratory protecting materials with upgraded safety levels.
基金This work was supported by the National Institute of Advanced Industrial Science and Technology,and the National Natural Science Foundation of China(NSFC-21875207).
文摘Through partial deligandation of metal-organic frameworks(MOFs),quasi-MOFs with a transition structure between MOFs and metal compounds(such as metal oxides,nitrides,sulfides,and phosphides)can be fabricated.Quasi-MOFs can not only retain the porous structure of MOFs to a certain extent,but also expose the inorganic nodes to the guest species(e.g.,metal nanoparticles)to show enhanced metal-support interaction for synergistic catalysis.This concept was first demonstrated by our group through calcining Au/MIL-101 at different temperatures under Ar flow to adjust the interface between Au nanoparticles and the inorganic Cr–O nodes.The obtained Au/quasi-MIL-101 showed superior enhanced catalytic activity in the oxidation of carbon monoxide.This study has inspired further research interest to fabricate other quasi-MOFs through controlled deligandation of mono-and bimetallic MOFs and their composites for the design of efficient catalysts.
基金the National Natural Science Foundation of China(Nos.21701187,21701160)Natural Science Basic Research Program of Shaanxi(No.2020JQ-142)the Fundamental Research Funds for the Central Universities(No.31020180QD115).
文摘While metal nanoparticles(NPs)have shown great promising applications as heterogeneous catalysts,their agglomeration caused by thermodynamic instability is detrimental to the catalytic performance.To tackle this hurdle,we successfully prepared a functional and stable porphyrinic metal-organic framework(MOF),PCN-224-RT,as a host for encapsulating metal nanoparticles by direct stirring at room temperature.As a result,Pt@PCN-224-RT composites with well-dispersed Pt NPs can be constructed by introducing pre-synthesized Pt NPs into the precursor solution of PCN-224-RT.Of note,the rapid and simple stirring method in this work is more in line with the requirements of environmental friendly and industrialization compared with traditional solvothermal methods.
文摘This review summarizes the utilization of supported noble metal nanoparticles (such as Au/TiO2, Au/ZrO2, Ag/AgCl) as efficient photo/sono-catalysts for the selective synthesis of chemicals and degradation of environmental pollutants. Supported noble metal nanoparticles could efficiently catalyze the conversion of solar energy into chemical energy. Under UV/visible light irradiation, important chemical transformations such as the oxidation of alcohols to carbonyl compounds, the oxidation of thiol to disulfide, the oxidation of benzene to phenol, and the reduction of nitroaromatic compounds to form aromatic azo compounds, are effectively achieved by supported noble metal nanoparticles. Under ultrasound irradiation, supported noble metal nanoparticles could efficiently catalyze the production of hydrogen from water. Moreover, various pollutants, including aldehydes, alcohols, acids, phenolic compounds, and dyes, can be effectively decomposed over supported noble metal nanoparticles under UV/visible light irradiation. Under ultrasound irradiation, pollutant molecules can also be completely degraded with supported noble metal nanoparticles as catalysts.
基金the funding support from the National Basic Research Program of China(2014CB931800,2013CB933900)the National Natural Science Foundation of China(21407140,21431006,91022032,91227103)+1 种基金J.Zhang is grateful for the China Postdoctoral Science Foundation(2013M531515)the Fundamental Research Funds for the Central Universities(WK2060190036)
文摘Herein, we report a plasmonic metal nanoparti- cle-involved sensor for cyanide ion based on the inner filter effect by using photoluminescent carbon dots as the signal reporter. With commercial bee pollen as the carbon resource, we synthesized photoluminescent nitrogen-doped carbon dots by a one-pot hydrothermal process, and their fluores- cence quantum yield reached as high as 10.2 % ± 0.5 %. Fluorescence measurements indicated that the fluorescence of the carbon dots was insusceptible to the presence of many environmentally ordinary ions. Thanks to this “inert” property, we then developed a turn-on fluorescent sensor for cyanide ion in an inner filter effect manner by using carbon dots as the fluorophore and gold or silver nanoparticle as the light absorber. This detection technique is expected to be used for other metal nanoparticles-carbon dots ensemble fluorescent assays.
基金supported by the Zhejiang Provincial Natural Science Foundation of China(No.LGF20C050001)the National Nature Science Foundation of China(No.61805213)。
文摘We use the method of discrete dipole approximation with surface interaction to construct a model in which a plurality of nanoparticles is arranged on the surface of BK7 glass. Nanoparticles are in air medium illuminated by evanescent wave generated from total internal reflection. The effects of the wavelength, the polarization of the incident wave, the number of nanoparticles and the spacing of multiple nanoparticles on the field enhancement and extinction efficiency are calculated by our model. Our work could pave the way to improve the field enhancement of multiple nanoparticles systems.
文摘The realization of plasmonic structures generally necessitates expensive fabrication techniques, such as electron beam and focused ion beam lithography, allowing for the top-down fabrication of low-dimensional structures. Another approach to make plasmonic structures in a bottom-up fashion is colloidal synthesis, which is convenient for liquid-state applications or very thin solid films where aggregation problems are an important challenge. The architectures prepared using these methods are typically not robust enough for easy handling and convenient integration. Therefore, developing a new plasmonic robust platform having large-scale dimensions without adversely affecting the plasmonic features is in high demand. As a solution, here we present a new plasmonic composite structure consisting of gold nanoparticles (Au NPs) incorporated into sucrose macrocrystals on a large scale, while preserving the plasmonic nature of the Au NPs and providing robustness in handling at the same time. As a proof of concept demonstration, we present the fluorescence enhancement of green CdTe quantum dots (QDs) via plasmonic coupling with these Au NPs in the sucrose crystals. The obtained composite material exhibits centimeter scale dimensions and the resulting quantum efficiency (QE) is enhanced via the interplay between the Au NPs and CdTe QDs by 58% (from 24% to 38%). Moreover, a shortening in the photoluminescence lifetime from 11.0 to 7.40 ns, which corresponds to a field enhancement factor of 2.4, is observed upon the introduction of Au NPs into the QD incorporated macrocrystals. These results suggest that such "sweet" plasmonic crystals are promising for large-scale robust platforms to embed plasmonic nanoparticles.
基金supported by the National Science Funds for Distinguished Young Scholars(No.21625401)the National Natural Science Foundation(Nos.21727808 and 21971114)+1 种基金the Jiangsu Provincial Founds for Natural Science Foundation(No.BK20200090)National Key R&D Program of China(No.2017YFA0207201).
文摘Fabrication of multifunctional catalysts has always been the pursuit of synthetic chemists due to their efficiency,cost-effectiveness,and environmental friendliness.However,it is difficult to control multi-step reactions in one-pot,especially the spatial compartmentalization of incompatible active sites.Herein,we constructed metal-organic framework(MOF)composites which regulate the location distribution of metal nanoparticles according to the reaction path and coupled with the diffusion of substrates to achieve tandem reaction.The designed UiO-66-Pt-Au catalyst showed good activity and selectivity in hydrosilylation-hydrogenation tandem reaction,because the uniform microporous structures can control the diffusion path of reactants and intermediates,and Pt and Au nanoparticles were arranged in core-shell spatial distribution in UiO-66.By contrast,the low selectivity of catalysts with random deposition and physical mixture demonstrated the significance of artificial control to the spatial compartmentalization of active sites in tandem catalytic reactions,which provides a powerful approach for designing high-performance and multifunctional heterogeneous catalysts.
基金This work was partially supported by the National Natural Science Foundation of China (Grant Nos. 51308312 and 41230638).
文摘In this study, stabilized Pd, Pt and Au nanoparticles were successfully prepared in aqueous phase using sodium carboxymethyl cellulose (CMC) as a capping agent. These metal nanoparticles were then tested for catalytic hydrodechlorination toward two classes of organochlorinated compounds (vinyl polychlorides includ- ing trichloroethylene (TCE), tetrachloroethylene (PCE), and alkyl polychlorides including 1,1,1-trichloroethane (1,1,1-TCA), and 1,1,1,2-tetrachloroethane (1,1,1,2- TeCA)) to determine the rate-limiting steps and to explore the reaction mechanisms. The surface area normalized reaction rate constant, ksA, showed a systematic depen- dence on the electronic structure (the density of states at the Fermi level) of the metals, suggesting that adsorption of organochlorinated reactants on the metal catalyst surfaces is the rate-limiting step for catalytic hydrodechlorination. Hydrodechlorination rates of 1,1,1-TCA and 1,1,1,2-TeCA agreed with the bond strength of the first (weakest) dissociated C-C1 bond, suggesting that C-C1 bond cleavage, which is the first step for dissociative adsorption of the alkyl polychlorides, controlled the catalytic hydro- dechlorination rate. However, hydrodechlorination rates of TCE and PCE correlated with the adsorption energies of their molecular (non-dissociative) adsorption on the noble metals rather than with the first C-C1 bond strength, suggesting that molecular adsorption governs the reaction rate for hydrodechlorination of the vinyl polychlorides.
基金the National Key R&D Program of China(No.2018YFC1705106)National Natural Science Foundation of China(No.51890893)。
文摘Photothermal therapy is emerging as a very promising way for minimally invasive cancer treatment.To enhance thermal energy deposition of laser in target malignant tissues,liquid metal nanoparticles(LMNPs)have been recently identified as completely unprecedented photothermal sensitizers due to their unique physicochemical properties and superior photothermal conversion rate under near-infrared(NIR)laser irradiation.However,there is currently a strong lack of understanding of the laser energy distribution and the transient temperature field within the biological tissues,which would seriously hinder the development of LMNPs assisted photothermal therapy.Therefore,this paper focused on the distinctive photothermal effect of LMNPs embedded in biological tissues under NIR laser irradiation.The mathematical model coupling the Monte-Carlo photon transport model with Penne's bioheat transfer model has been established.Simulation studies have shown that LMNPs play an important role in enhancing the absorption of NIR laser,which contributes to local temperature rise and improves the temperature distribution.Comparing with the control case without LMNPs,the maximum temperature increases by nearly 1.0 time,the local temperature rise reaches 30℃ in 1.0 second.When the diameter and concentration of LMNPs are 40 nm and 1012/mm3,the resulting temperature variation and distribution is best for the effective killing of tumors without damaging normal tissues.In addition,the simulation results are meaningful for guiding the selection of laser irradiation time in conjunction with the cooling time,ensuring the controllable accuracy of treatment.To the best of our knowledge,the present study is one of the first attempts to quantify the influence of transformable LMNPs on the temperature distributions inside the biological tissues,showing important academic significance for guiding LMNPs assisted photothermal treatment.
基金supported by the National Natural Science Foundation of China(21902097,21636006 and 21761132025)the China Postdoctoral Science Foundation(2019M653861XB)+1 种基金the Natural Science Foundation of Shaanxi Province(2020JQ-409)the Fundamental Research Funds for the Central Universities(GK201901001 and GK202003035)。
文摘Oxidative dehydrogenation of propane with carbon dioxide(CO_(2)-ODP)characterizes the tandem dehydrogenation of propane to propylene with the reduction of the greenhouse gas of CO_(2)to valuable CO.However,the existing catalyst is limited due to the poor activity and stability,which hinders its industrialization.Herein,we design the finned Zn-MFI zeolite encapsulated noble metal nanoparticles(NPs)as bifunctional catalysts(NPs@Zn-MFI)for CO_(2)-ODP.Characterization results reveal that the Zn2+species are coordinated with the MFI zeolite matrix as isolated cations and the NPs of Pt,Rh,or Rh Pt are highly dispersed in the zeolite crystals.The isolated Zn2+cations are very effective for activating the propane and the small NPs are favorable for activating the CO_(2),which synergistically promote the selective transformation of propane and CO_(2)to propylene and CO.As a result,the optimal 0.25%Rh0.50%Pt@Zn-MFI catalyst shows the best propylene yield,satisfactory CO_(2)conversion,and long-term stability.Moreover,considering the tunable synergetic effects between the isolated cations and NPs,the developed approach offers a general guideline to design more efficient CO_(2)-ODP catalysts,which is validated by the improved performance of the bifunctional catalysts via simply substituting Sn4+cations for Zn2+cations in the MFI zeolite matrix.