The monodisperse Au@Ag bimetallic nanorod is encapsulated by crosslinked poly( N-isopropylacrylamide)( PNIPAM) to produce thermo-responsive composite microgel with well-defined core-shell structure( Au@ Ag NR@ PNIPAM ...The monodisperse Au@Ag bimetallic nanorod is encapsulated by crosslinked poly( N-isopropylacrylamide)( PNIPAM) to produce thermo-responsive composite microgel with well-defined core-shell structure( Au@ Ag NR@ PNIPAM microgel)by seed-precipitation polymerization method using butenoic acid modified Au @ Ag NRs as seeds. When the temperature of the aqueous medium increases from 20℃ to 50℃,the localized surface plasmon resonance( LSPR) band of the entrapped Au @ Ag NR is pronouncedly red-shifted because of the decreased spatial distances between them as a result of shrinkage of the microgels,leading to their plasmonic coupling. The temperature tunable plasmonic coupling is demonstrated by temperature dependence of the surface enhanced Raman spectroscopy( SERS) signal of 1-naphthol in aqueous solution. Different from static plasmonic coupling modes from nanostructured assembly or array system of noble metals,the proposed plasmonic coupling can be dynamically controlled by environmental temperature. Therefore, the thermo responsive hybrid microgels have potential applications in mobile LSPR or SERS microsensors for living tissues or cells.展开更多
A clear light-yellow silver sol which has the visible spectral absorption at 390 nm, when adsorbed phenylmercaptotetrazole(PMT) or mercaptobenzothiazole(MBT), has a new absorption at 510-550 nm. It was found that the ...A clear light-yellow silver sol which has the visible spectral absorption at 390 nm, when adsorbed phenylmercaptotetrazole(PMT) or mercaptobenzothiazole(MBT), has a new absorption at 510-550 nm. It was found that the adsorption of halide ions competes with PMT and MBT. However, halide ions have a completely different influence from PMT and MBT on the spectral absorption of the silver sol. The differences may result from the change of the properties of the surface of the silver subcolloidal particles and from the bond forms combining adsorbates with the substrates.展开更多
Magnetic polyphosphazene(MPZS) particles coated by Ag nanoparticles(MPZS-Ag) have been developed as surface enhanced Raman spectroscopy(SERS) substrates for sensitive detection of melamine in aqueous solutions and mil...Magnetic polyphosphazene(MPZS) particles coated by Ag nanoparticles(MPZS-Ag) have been developed as surface enhanced Raman spectroscopy(SERS) substrates for sensitive detection of melamine in aqueous solutions and milk samples.5,5’-Dithiobis-(2-nitrobenzoic acid)(DTNB) was used as model analyte to test the SERS activity of the MPZS-Ag particles.The prepared MPZS-Ag particles possess both magnetic responsiveness and excellent SERS properties.SERS detection of different concentrations of melamine aqueous solutions and spiked milk samples were performed by the MPZS-Ag particles.The limit of detection(LOD) of the melamine in aqueous solutions was 10^-7 mol/L(0.0126 mg/L) and 0.6 mg/L in real milk samples using the MPZS-Ag particles as SERS substrates.The LOD of the melamine are much lower than the safety values of Food and Drug Administration and Codex Alimentarius Commission.These results indicate that the MPZS-Ag particles have promising application prospect for SERS analysis in food safety fields.展开更多
In this study,gold nanoparticles(AuNPs)were synthesized for rapid and sensitive characterization and quantification of chlorpyrifos in apples.Min-max signal adaptive zooming and second derivative transformation method...In this study,gold nanoparticles(AuNPs)were synthesized for rapid and sensitive characterization and quantification of chlorpyrifos in apples.Min-max signal adaptive zooming and second derivative transformation method were adopted to pre-process Raman spectral signal.The min-max signal adaptive zooming method showed a higher correlation coefficient than derivative transformation when developing linear calibration curve between chlorpyrifos pesticide and Raman spectral peak intensity.The present method had a high reproducibility with the relative standard deviation less than 15%.Regression models showed a good linear relationship(R=0.962)between intensity of characteristic spectral peaks(at 677 cm-1)and chlorpyrifos concentration on whole apples ranging from 0.13 mg/kg to 7.59 mg/kg.The application of surface enhancement Raman spectroscopy(SERS)detected chlorpyrifos pesticide to the detection limit of 0.13 mg/kg,which can be applied further for lower concentration in the future.The method presented in this study can provide a way-out for detection of pesticide residue in whole apple to trace amount.展开更多
Contamination by accidental cutaneous contact with the commercial products and the air pol-hutants raised a considerable health and safety issue.This study aimed to trace the dynamics of the 20 nm gold nanopartide(GNP...Contamination by accidental cutaneous contact with the commercial products and the air pol-hutants raised a considerable health and safety issue.This study aimed to trace the dynamics of the 20 nm gold nanopartide(GNP)penetration and accumulation in rat skin tissues using a surface-enhanced Raman scattering(SERS)techmique.After the topical application of GNPs on rat skin surface,the SERS spectra were recorded for every 15 pum to an overall depth of 75 pum from skin surface for 150 min.The processes of GNP penetration in rat skin were accompanied by aggregation of GNPs,which affected SERS spectra.The results revealed that 20 nm GNPs can penetrate through stratum corneum layer,viable epidermis layer,and then into dermis layer.This study demonstrated for the first time the potential of SERS spectroscopy to monitor the penetration and accumulation of GNPs in rat skin.展开更多
Residual pesticides such as phosmet and chlorpyrifos in fruit have become a public concern problem in recent years.In this study,surface-enhanced Raman spectroscopy(SERS)was used to detect and characterize pesticides ...Residual pesticides such as phosmet and chlorpyrifos in fruit have become a public concern problem in recent years.In this study,surface-enhanced Raman spectroscopy(SERS)was used to detect and characterize pesticides extracted from navel orange surfaces.Silver colloid was prepared for getting the SERS of phosmet and chlorpyrifos.Enhanced Raman signals of phosmet over a concentration range of 5 mg/L to 30 mg/L and chlorpyrifos over a concentration range of 5 mg/L to 20 mg/L were acquired.Partial least squares(PLS)regression combined with different data preprocessing methods was used to develop quantitative models.With the second derivative data preprocessing,the best prediction model of phosmet pesticide was achieved with a correlation coefficient(r)of 0.852 and the root mean square error of prediction(RMSEP)of 5.177 mg/L.The best prediction model of chlorpyrifos pesticide was achieved with r of 0.843 and the RMSEP of 2.992 mg/L using the multiplicative scatter correction(MSC)and first derivative data preprocessing.This study indicated that SERS coupled with Ag nanostructures is a potential tool for analysis of phosmet and chlorpyrifos pesticide residues.展开更多
Novel hollow Au Ag alloy nano urchins were synthesized via Ag seeds growth method,and self-assembly coated on the wall and end-tip of silica fiber for fiber probe fabrication.The nano urchins homogeneously distributed...Novel hollow Au Ag alloy nano urchins were synthesized via Ag seeds growth method,and self-assembly coated on the wall and end-tip of silica fiber for fiber probe fabrication.The nano urchins homogeneously distributed on fiber surface because of fiber silanization.The sizes and tip sharpness of the nano-urchins could be controlled by Ag seeds.The elements distribution analysis indicated there was high Ag content in tip-top for better surface enhance Raman scattering performance.The detectable concentration could be as low as 10-8 M using crystal violet molecules as analyte.Moreover,the fiber probes were stable in air,due to Au in the alloy.This fiber probe could be used for low content single molecular analysis.展开更多
The development of efficient three-dimensional cell imaging technology is a necessary means to study cell composition and structure,especially to track and monitor the phagocytosis process of nanoparticles by cells.He...The development of efficient three-dimensional cell imaging technology is a necessary means to study cell composition and structure,especially to track and monitor the phagocytosis process of nanoparticles by cells.Herein,we prepared a MoO_(2)hollow nanosphere with a strong surface plasmon resonance effect in the visible light region,which exhibited an excellent surface enhanced Raman scattering effect.When the 4-mercaptobenzoic acid(4-MBA)molecules are modified,it can be efficiently used as Raman probe molecules to perform clear three-dimensional cell imaging.No matter when the nanoparticles are located inside the cell,outside the cell or partly inside the cell,they all can be clearly presented by this enhanced Raman probe molecule.These results provide a rapid and accurate method for three-dimensional imaging of cells,especially for tracking the phagocytosis of nanoparticles.展开更多
The structure and dynamics of electrode/liquid interfaces play an increasingly important role in electrochemistry. Raman spectroscopy is capable of providing detailed structural information at molecular level and new ...The structure and dynamics of electrode/liquid interfaces play an increasingly important role in electrochemistry. Raman spectroscopy is capable of providing detailed structural information at molecular level and new insight into the interfacial structure, adsorption, reaction, electrocatalysis and corrosion. In this account we will summarize some progresses of surface Raman spectroscopy in the study of electrochemical interfaces, mainly based on our group's work, laying emphasis on the detection sensitivity, spectral resolution, time resolution and spatial resolution as well as the hyphenated technique.展开更多
In the present work,a new combination of Raman and ultraviolet and visible(UV/Vis)absorption spectroelectrochemistry in reflection mode is proposed.The new experimental setup allows obtaining the two kinds of spectros...In the present work,a new combination of Raman and ultraviolet and visible(UV/Vis)absorption spectroelectrochemistry in reflection mode is proposed.The new experimental setup allows obtaining the two kinds of spectroscopic data without interferences concomitantly with the electrochemical information.To the best of our knowledge,it is the first time to report the simultaneous obtention of electrochemical,electronic,and vibrational information in the same experiment.This new combination provides time-resolved information about the processes that are taking place on the electrode/solution interface which has significant implications in different fields of chemistry,such as modification of electrodes,studies of electrocatalytic reaction mechanisms,development of sensors,among others.Two different systems were used to demonstrate the advantages and capabilities of the brand-new technique,namely,the oxidation of potassium ferrocyanide,an out-sphere system that is usually employed in the validation of SEC techniques,and the electrochemical-surface enhanced Raman spectroscopy(EC-SERS)detection of crystal violet by in-situ formation of the silver SERS substrate,where the UV/Vis spectra were used to follow the formation of the SERS substrate,whereas the Raman response of a probe molecule was used to confirm either the formation of a nanostructured surface and to obtain the fingerprint of the molecule with a high time resolution.The brand-new experimental setup has shown to be useful,versatile,robust,compact,and easy to use for future applications.展开更多
When aprotic Li-O_2 batteries recharge, the solid Li_2O_2 in the positive electrode is oxidized, which often exhibits a continuous or step increase in the charging potential as a function of the charging capacity, and...When aprotic Li-O_2 batteries recharge, the solid Li_2O_2 in the positive electrode is oxidized, which often exhibits a continuous or step increase in the charging potential as a function of the charging capacity, and its origin remains incompletely understood.Here, we report a model study of electro-oxidation of a Li_2O_2 film on an Au electrode using voltammetry coupled with in situ Raman spectroscopy. It was found that the charging reaction initializes at the positive electrode|Li_2O_2 interface, instead of the previously presumed Li_2O_2 surface, and consists of two temporally and spatially separated Li_2O_2 oxidation processes, accounting for the potential rise during charging of Li-O_2 batteries. Moreover, the electrode surface-initialized oxidation can disintegrate the Li_2O_2 film resulting in a loss of Li_2O_2 into electrolyte solution, which drastically decreases the charging efficiency and highlights the importance of using soluble electro-catalyst for the complete charging of Li-O_2 batteries.展开更多
Of late, many synthesis processes have been studied to develop irregular nano-rnorphologies of gold nanostructures for biomedical applications in order to increase the efficacy of nanoparticle theranostics, tune the p...Of late, many synthesis processes have been studied to develop irregular nano-rnorphologies of gold nanostructures for biomedical applications in order to increase the efficacy of nanoparticle theranostics, tune the plasmonic absorbance spectra, and increase the sensitivity of biomolecule detection through surface enhanced Raman spectroscopy. Here we report, a novel, non-seed mediated versatile single pot synthesis method capable of producing hyperbranched gold "nano-polyvilli" with more than 50-90 branching nanowires propagating from a single origin within each structure. The technique was capable of achieving precise tuning of the branch propagation where the branching could be controlled by varying the duration of incubation, temperature, and hydrogen ion concentration.展开更多
Emerging single-cell technologies create new opportunities for unraveling tumor heterogeneity.However,the development of high-content phenotyping platform is still at its infancy.Here,we develop a microfluidic chip fo...Emerging single-cell technologies create new opportunities for unraveling tumor heterogeneity.However,the development of high-content phenotyping platform is still at its infancy.Here,we develop a microfluidic chip for two-dimensional(2D)profiling of tumor chemotactic and molecular features at single cell resolution.Individual cells were captured by the triangular micropillar arrays in the cell-loading channel,facilitating downstream single-cell analysis.For 2D phenotyping,the chemotactic properties of tumor cells were visualized through cellular migratory behavior in microchannels,while their protein expression was profiled with multiplex surface enhanced Raman scattering(SERS)nanovectors,in which Raman reporter-embedded gold@silver core-shell nanoparticles(Au@Ag REPs)were modified with DNA aptamers targeting cellular surface proteins.As a proof of concept,breast cancer cells with diverse phenotypes were tested on the chip,demonstrating the capability of this platform for simultaneous chemotactic and molecular analysis.The chip is expected to provide a powerful tool for investigating tumor heterogeneity and promoting clinical precision medicine.展开更多
Hydrogen peroxide(H_(2)O_(2))is an important chemical substance produced in the metabolic process of organisms.Excess or less production could lead to serious effects on the body.Therefore,the development of advanced ...Hydrogen peroxide(H_(2)O_(2))is an important chemical substance produced in the metabolic process of organisms.Excess or less production could lead to serious effects on the body.Therefore,the development of advanced technology to accurately detect the content of H_(2)O_(2) is of great significance.Herein,we developed a new ratiometric SERS nanoprobe based on shell-isolated nanoparticles(SHINs)for rapidly quantitative detection of H_(2)O_(2)-Because of the small Raman cross-section of H_(2)O_(2),the ratiometric nanoprobe is an effective method for indirect detection of H_(2)O_(2),which is designed based on the reaction of p-mercaptophenylboric acid(MPB)with H_(2)O_(2) to form p-mercaptophenol(MP).Meanwhile,the nanoprobe was used to achieve quantitative detection of H_(2)O_(2) and applied in quantitative detection of actual sample-glucose,whose linear correlation coefficient could reach 0.9947 and 0.9812,respectively.This method expands the application of SERS technology,especially provides a reference for the detection of molecules with small Raman cross-section.展开更多
基金National Natural Science Foundation of China(No.51373030)Chinese Universities Scientific Fund(No.CUSF-DH-D-2014023)
文摘The monodisperse Au@Ag bimetallic nanorod is encapsulated by crosslinked poly( N-isopropylacrylamide)( PNIPAM) to produce thermo-responsive composite microgel with well-defined core-shell structure( Au@ Ag NR@ PNIPAM microgel)by seed-precipitation polymerization method using butenoic acid modified Au @ Ag NRs as seeds. When the temperature of the aqueous medium increases from 20℃ to 50℃,the localized surface plasmon resonance( LSPR) band of the entrapped Au @ Ag NR is pronouncedly red-shifted because of the decreased spatial distances between them as a result of shrinkage of the microgels,leading to their plasmonic coupling. The temperature tunable plasmonic coupling is demonstrated by temperature dependence of the surface enhanced Raman spectroscopy( SERS) signal of 1-naphthol in aqueous solution. Different from static plasmonic coupling modes from nanostructured assembly or array system of noble metals,the proposed plasmonic coupling can be dynamically controlled by environmental temperature. Therefore, the thermo responsive hybrid microgels have potential applications in mobile LSPR or SERS microsensors for living tissues or cells.
文摘A clear light-yellow silver sol which has the visible spectral absorption at 390 nm, when adsorbed phenylmercaptotetrazole(PMT) or mercaptobenzothiazole(MBT), has a new absorption at 510-550 nm. It was found that the adsorption of halide ions competes with PMT and MBT. However, halide ions have a completely different influence from PMT and MBT on the spectral absorption of the silver sol. The differences may result from the change of the properties of the surface of the silver subcolloidal particles and from the bond forms combining adsorbates with the substrates.
基金the financial support of the National Natural Science Foundation of China(Nos.51503040,31771893)the Natural Science Foundation of Fujian Province,China(No. 2018J01766)the Outstanding Youth Research Talent Cultivation Program of Universities in Fujian Province,China (No.601936)
文摘Magnetic polyphosphazene(MPZS) particles coated by Ag nanoparticles(MPZS-Ag) have been developed as surface enhanced Raman spectroscopy(SERS) substrates for sensitive detection of melamine in aqueous solutions and milk samples.5,5’-Dithiobis-(2-nitrobenzoic acid)(DTNB) was used as model analyte to test the SERS activity of the MPZS-Ag particles.The prepared MPZS-Ag particles possess both magnetic responsiveness and excellent SERS properties.SERS detection of different concentrations of melamine aqueous solutions and spiked milk samples were performed by the MPZS-Ag particles.The limit of detection(LOD) of the melamine in aqueous solutions was 10^-7 mol/L(0.0126 mg/L) and 0.6 mg/L in real milk samples using the MPZS-Ag particles as SERS substrates.The LOD of the melamine are much lower than the safety values of Food and Drug Administration and Codex Alimentarius Commission.These results indicate that the MPZS-Ag particles have promising application prospect for SERS analysis in food safety fields.
基金The authors wish to thank the National Key Technology R&D Program(Project No.2015BAD19B03 and 2013BAD19B02),China,for providing funding support for this research.
文摘In this study,gold nanoparticles(AuNPs)were synthesized for rapid and sensitive characterization and quantification of chlorpyrifos in apples.Min-max signal adaptive zooming and second derivative transformation method were adopted to pre-process Raman spectral signal.The min-max signal adaptive zooming method showed a higher correlation coefficient than derivative transformation when developing linear calibration curve between chlorpyrifos pesticide and Raman spectral peak intensity.The present method had a high reproducibility with the relative standard deviation less than 15%.Regression models showed a good linear relationship(R=0.962)between intensity of characteristic spectral peaks(at 677 cm-1)and chlorpyrifos concentration on whole apples ranging from 0.13 mg/kg to 7.59 mg/kg.The application of surface enhancement Raman spectroscopy(SERS)detected chlorpyrifos pesticide to the detection limit of 0.13 mg/kg,which can be applied further for lower concentration in the future.The method presented in this study can provide a way-out for detection of pesticide residue in whole apple to trace amount.
基金supported by the National Natural Science Foundation of China(No.61275187,No.61378089,and No.31300691).
文摘Contamination by accidental cutaneous contact with the commercial products and the air pol-hutants raised a considerable health and safety issue.This study aimed to trace the dynamics of the 20 nm gold nanopartide(GNP)penetration and accumulation in rat skin tissues using a surface-enhanced Raman scattering(SERS)techmique.After the topical application of GNPs on rat skin surface,the SERS spectra were recorded for every 15 pum to an overall depth of 75 pum from skin surface for 150 min.The processes of GNP penetration in rat skin were accompanied by aggregation of GNPs,which affected SERS spectra.The results revealed that 20 nm GNPs can penetrate through stratum corneum layer,viable epidermis layer,and then into dermis layer.This study demonstrated for the first time the potential of SERS spectroscopy to monitor the penetration and accumulation of GNPs in rat skin.
基金the National Science and Technology Support Program(31160250,61178036).
文摘Residual pesticides such as phosmet and chlorpyrifos in fruit have become a public concern problem in recent years.In this study,surface-enhanced Raman spectroscopy(SERS)was used to detect and characterize pesticides extracted from navel orange surfaces.Silver colloid was prepared for getting the SERS of phosmet and chlorpyrifos.Enhanced Raman signals of phosmet over a concentration range of 5 mg/L to 30 mg/L and chlorpyrifos over a concentration range of 5 mg/L to 20 mg/L were acquired.Partial least squares(PLS)regression combined with different data preprocessing methods was used to develop quantitative models.With the second derivative data preprocessing,the best prediction model of phosmet pesticide was achieved with a correlation coefficient(r)of 0.852 and the root mean square error of prediction(RMSEP)of 5.177 mg/L.The best prediction model of chlorpyrifos pesticide was achieved with r of 0.843 and the RMSEP of 2.992 mg/L using the multiplicative scatter correction(MSC)and first derivative data preprocessing.This study indicated that SERS coupled with Ag nanostructures is a potential tool for analysis of phosmet and chlorpyrifos pesticide residues.
基金Funded by the Project of Sanya Yazhou Bay Science and Technology City (No.SCKJ-JYRC-2022-44)the Opening Funding of the State Key Laboratory of Silicate Materials for Architecture (SySJJ2018-06)+1 种基金the Fundamental Research Funds for the Central Universities (WUT:2016VA096),Chinathe Research Program (No.S2634339)through a Grant Provided by the Ministry of SMEs and Startups。
文摘Novel hollow Au Ag alloy nano urchins were synthesized via Ag seeds growth method,and self-assembly coated on the wall and end-tip of silica fiber for fiber probe fabrication.The nano urchins homogeneously distributed on fiber surface because of fiber silanization.The sizes and tip sharpness of the nano-urchins could be controlled by Ag seeds.The elements distribution analysis indicated there was high Ag content in tip-top for better surface enhance Raman scattering performance.The detectable concentration could be as low as 10-8 M using crystal violet molecules as analyte.Moreover,the fiber probes were stable in air,due to Au in the alloy.This fiber probe could be used for low content single molecular analysis.
基金This work received financial support from the Science Foundation of Chinese Academy of Inspection and Quarantine(No.2017JK045)the National Key Research and Development Program of China(No.2017YFF0210003).
文摘The development of efficient three-dimensional cell imaging technology is a necessary means to study cell composition and structure,especially to track and monitor the phagocytosis process of nanoparticles by cells.Herein,we prepared a MoO_(2)hollow nanosphere with a strong surface plasmon resonance effect in the visible light region,which exhibited an excellent surface enhanced Raman scattering effect.When the 4-mercaptobenzoic acid(4-MBA)molecules are modified,it can be efficiently used as Raman probe molecules to perform clear three-dimensional cell imaging.No matter when the nanoparticles are located inside the cell,outside the cell or partly inside the cell,they all can be clearly presented by this enhanced Raman probe molecule.These results provide a rapid and accurate method for three-dimensional imaging of cells,especially for tracking the phagocytosis of nanoparticles.
基金Project supported by the National Nature Science Foundation of China and the Ministry of Education of China.
文摘The structure and dynamics of electrode/liquid interfaces play an increasingly important role in electrochemistry. Raman spectroscopy is capable of providing detailed structural information at molecular level and new insight into the interfacial structure, adsorption, reaction, electrocatalysis and corrosion. In this account we will summarize some progresses of surface Raman spectroscopy in the study of electrochemical interfaces, mainly based on our group's work, laying emphasis on the detection sensitivity, spectral resolution, time resolution and spatial resolution as well as the hyphenated technique.
基金support from Ministerio de Ciencia e innovación(No.PID2020-113154RB-C21)Ministerio de Economía,Industria y Competitividad(No.CTQ2017-83935-RAEI/FEDERUE)+4 种基金Junta de Castilla y León(No.BU297P18)Ministerio de Ciencia,Innovación y Universidades(No.RED2018-102412-T)J.V.P-R acknowledges Spanish Ministry of Economy,Industry,and Competitiveness for the Juan de la Cierva postdoctoral(No.FJCI-2017-32458)the University of Alcalá(No.CCG19/CC-071)S.H.thanks JCyL and European Social Fund for her predoctoral fellowship.
文摘In the present work,a new combination of Raman and ultraviolet and visible(UV/Vis)absorption spectroelectrochemistry in reflection mode is proposed.The new experimental setup allows obtaining the two kinds of spectroscopic data without interferences concomitantly with the electrochemical information.To the best of our knowledge,it is the first time to report the simultaneous obtention of electrochemical,electronic,and vibrational information in the same experiment.This new combination provides time-resolved information about the processes that are taking place on the electrode/solution interface which has significant implications in different fields of chemistry,such as modification of electrodes,studies of electrocatalytic reaction mechanisms,development of sensors,among others.Two different systems were used to demonstrate the advantages and capabilities of the brand-new technique,namely,the oxidation of potassium ferrocyanide,an out-sphere system that is usually employed in the validation of SEC techniques,and the electrochemical-surface enhanced Raman spectroscopy(EC-SERS)detection of crystal violet by in-situ formation of the silver SERS substrate,where the UV/Vis spectra were used to follow the formation of the SERS substrate,whereas the Raman response of a probe molecule was used to confirm either the formation of a nanostructured surface and to obtain the fingerprint of the molecule with a high time resolution.The brand-new experimental setup has shown to be useful,versatile,robust,compact,and easy to use for future applications.
基金supported by the National Natural Science Foundation of China (91545129, 21575135, 21605136)the “Strategic Priority Research Program” of the Chinese Academy of Science (XDA09010401)+1 种基金the National Key Technology Research and Development Program of China (2016YBF0100100)the Science and Technology Development Program of the Jilin Province (20150623002TC, 20160414034GH)
文摘When aprotic Li-O_2 batteries recharge, the solid Li_2O_2 in the positive electrode is oxidized, which often exhibits a continuous or step increase in the charging potential as a function of the charging capacity, and its origin remains incompletely understood.Here, we report a model study of electro-oxidation of a Li_2O_2 film on an Au electrode using voltammetry coupled with in situ Raman spectroscopy. It was found that the charging reaction initializes at the positive electrode|Li_2O_2 interface, instead of the previously presumed Li_2O_2 surface, and consists of two temporally and spatially separated Li_2O_2 oxidation processes, accounting for the potential rise during charging of Li-O_2 batteries. Moreover, the electrode surface-initialized oxidation can disintegrate the Li_2O_2 film resulting in a loss of Li_2O_2 into electrolyte solution, which drastically decreases the charging efficiency and highlights the importance of using soluble electro-catalyst for the complete charging of Li-O_2 batteries.
文摘Of late, many synthesis processes have been studied to develop irregular nano-rnorphologies of gold nanostructures for biomedical applications in order to increase the efficacy of nanoparticle theranostics, tune the plasmonic absorbance spectra, and increase the sensitivity of biomolecule detection through surface enhanced Raman spectroscopy. Here we report, a novel, non-seed mediated versatile single pot synthesis method capable of producing hyperbranched gold "nano-polyvilli" with more than 50-90 branching nanowires propagating from a single origin within each structure. The technique was capable of achieving precise tuning of the branch propagation where the branching could be controlled by varying the duration of incubation, temperature, and hydrogen ion concentration.
基金This study was supported by the National Science Fund for Excellent Young Scholars(No.61822503)the National Natural Science Foundation of China(Nos.62175030 and 62175027)+3 种基金China Postdoctoral Science Foundation(No.2021TQ0147)Jiangsu Innovation and Entrepreneurship Program(No.JSSCBS20210126)Nanjing Science and Technology Innovation Project for Returned Overseas Chinese Scholars(No.1106000308)the Fundamental Research Funds for the Central Universities(Nos.3206002104D and 3206002108A1).
文摘Emerging single-cell technologies create new opportunities for unraveling tumor heterogeneity.However,the development of high-content phenotyping platform is still at its infancy.Here,we develop a microfluidic chip for two-dimensional(2D)profiling of tumor chemotactic and molecular features at single cell resolution.Individual cells were captured by the triangular micropillar arrays in the cell-loading channel,facilitating downstream single-cell analysis.For 2D phenotyping,the chemotactic properties of tumor cells were visualized through cellular migratory behavior in microchannels,while their protein expression was profiled with multiplex surface enhanced Raman scattering(SERS)nanovectors,in which Raman reporter-embedded gold@silver core-shell nanoparticles(Au@Ag REPs)were modified with DNA aptamers targeting cellular surface proteins.As a proof of concept,breast cancer cells with diverse phenotypes were tested on the chip,demonstrating the capability of this platform for simultaneous chemotactic and molecular analysis.The chip is expected to provide a powerful tool for investigating tumor heterogeneity and promoting clinical precision medicine.
基金Supported by the National Natural Science Foundation of China(21925404)the Science and Technology Planning Project of Fujian Province(2019Y4001)。
文摘Hydrogen peroxide(H_(2)O_(2))is an important chemical substance produced in the metabolic process of organisms.Excess or less production could lead to serious effects on the body.Therefore,the development of advanced technology to accurately detect the content of H_(2)O_(2) is of great significance.Herein,we developed a new ratiometric SERS nanoprobe based on shell-isolated nanoparticles(SHINs)for rapidly quantitative detection of H_(2)O_(2)-Because of the small Raman cross-section of H_(2)O_(2),the ratiometric nanoprobe is an effective method for indirect detection of H_(2)O_(2),which is designed based on the reaction of p-mercaptophenylboric acid(MPB)with H_(2)O_(2) to form p-mercaptophenol(MP).Meanwhile,the nanoprobe was used to achieve quantitative detection of H_(2)O_(2) and applied in quantitative detection of actual sample-glucose,whose linear correlation coefficient could reach 0.9947 and 0.9812,respectively.This method expands the application of SERS technology,especially provides a reference for the detection of molecules with small Raman cross-section.