The coupling of local surface plasmon （LSP） of nanoparticle and surface plasmon （SP） mode produced by metal film can lead to the enhanced electromagnetic field, which has an important application in enhancing the ...The coupling of local surface plasmon （LSP） of nanoparticle and surface plasmon （SP） mode produced by metal film can lead to the enhanced electromagnetic field, which has an important application in enhancing the fluorescence of quantum dots （QDs）. Herein, the Ag nanocube and Ag film are used to enhance the fluorescence of CdSe QDs. The enhancement is found to relate to the sizes of the Ag nanocube and the thickness of the Ag film. Moreover, we also present the fluorescence enhancement caused by only SP. The result shows that the coupling between metal nanoparticles and metal film can realize larger field enhancement. Numerical simulation verifies that a nanocube can localize a strong electric field around its comer. All the results indicate that the fluorescence of QDs can be efficiently improved by optimizing the parameters of Ag film and Ag cubes.展开更多
Ag nanocubes-reduced graphene oxide（AgNCs-rGO） nanocomposite was successfully prepared by an in situ synthesis method, in which AgNCs were loaded onto the surface of rGO during the formation of AgNCs in an ethylene ...Ag nanocubes-reduced graphene oxide（AgNCs-rGO） nanocomposite was successfully prepared by an in situ synthesis method, in which AgNCs were loaded onto the surface of rGO during the formation of AgNCs in an ethylene glycol solution. Characterization by X-ray diffraction, UV-Vis spectroscopy, and scanning electron microscopy indicated the successful preparation of the AgNCs-rGO nanocomposite. Most importantly, the AgNCs-rGO nanocomposite exhibited excellent electrocatalytic activity for the reduction of H2O2, leading to a high-performance non-enzymatic H2O2 sensor with a linear detection range and detection limit of approximately 0.1 mmol/L to 70 mmol/L（r=0.999） and 0.58 μmol/L, respectively. Our present work provides a new and highly efficient method for fabricating high-performance electrochemical sensors.展开更多
Gold （Au） nanocage@SiO2 nanoparticles are prepared by a novel approach. The silver （Ag） nanocube@SiO2 structure is synthetized firstly. Next, the method of etching a SiO2 shell by boiling water is adopted to chang...Gold （Au） nanocage@SiO2 nanoparticles are prepared by a novel approach. The silver （Ag） nanocube@SiO2 structure is synthetized firstly. Next, the method of etching a SiO2 shell by boiling water is adopted to change the penetration rate of AuCl4- through the SiO2 shell. AuCl4- can penetrate through silica shells of different thickness values to react with the Ag nanocube core by changing the incubation time. The surface plasma resonance （SPR） peak of synthetic Au nanocage@SiO2 can be easily tuned into the near-infrared region. Besides, CdTeS quantum dots （QDs） are successfully connected to the surface of Au nanocage@SiO2, which testifies that the incubation process does not change the property of silica.展开更多
Surface-enhanced Raman spectroscopy （SERS） is a fast analytical technique for trace chemicals; however, it requires the active SERS-substrates to adsorb analytes, thus limiting target species to those with the desir...Surface-enhanced Raman spectroscopy （SERS） is a fast analytical technique for trace chemicals; however, it requires the active SERS-substrates to adsorb analytes, thus limiting target species to those with the desired affinity for substrates. Here we present networked polyacrylic acid sodium salt （PAAS） film entrapped Ag-nanocubes （denoted as Ag-nanocubes@PAAS） as an effective SERS-substrate for analytes with and without high affinity. Once the analyte aqueous solution is cast on the dry Ag-nanocubes@PAAS substrate, the bibulous PAAS becomes swollen forcing the Ag-nanocubes loose, while the analytes diffuse in the interstices among the Ag-nanocubes. When dried, the PAAS shrinks and pulls the Ag-nanocubes back to their previous aggregated state, while the PAAS network ＂detains＂ the analytes in the small gaps between the Ag-nanocubes for SERS detection. The strategy has been proven effective for not only single- analytes but also multi-analytes without strong affinity for Ag, showing its potential in SERS-based simultaneous multi-analyte detection of both adsorbable and non-adsorbable pollutants in the environment.展开更多
The controllable synthesis of uniform silver nanocubes with high purity is pivotal for the fundamental study of self-assembly and further research on the hollow nanostructures,gold nanocages for instance.Here,Ag nanoc...The controllable synthesis of uniform silver nanocubes with high purity is pivotal for the fundamental study of self-assembly and further research on the hollow nanostructures,gold nanocages for instance.Here,Ag nanocubes of different sizes were synthesized by an improved polyol method.With addition of HCl solution,Ag nanocubes with size about 100 nm were obtained under an air atmosphere.And Ag nanocubes with size around50 nm can be produced in a short time under Argon atmosphere with the presence of NaHS instead of HCl.Meanwhile,uniform Ag nanocubes with size larger than 100 nm were also synthesized successfully via adjusting experiment parameters.Results of transmission electron microscopy(TEM)combined with selected area electron diffraction(SAED)show that the Ag nanocubes are single crystalline with six(200)surface plane.In the UV-Vis-NIR optical absorption spectrum,the diple moment resonance absorption peak is changed in the range of 420—500nm with the increase of Ag nanocubes size.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51272246 and 81172082)the Fundamental Research Funds for the Central Universities,China(Grant No.2030000001)
文摘The coupling of local surface plasmon （LSP） of nanoparticle and surface plasmon （SP） mode produced by metal film can lead to the enhanced electromagnetic field, which has an important application in enhancing the fluorescence of quantum dots （QDs）. Herein, the Ag nanocube and Ag film are used to enhance the fluorescence of CdSe QDs. The enhancement is found to relate to the sizes of the Ag nanocube and the thickness of the Ag film. Moreover, we also present the fluorescence enhancement caused by only SP. The result shows that the coupling between metal nanoparticles and metal film can realize larger field enhancement. Numerical simulation verifies that a nanocube can localize a strong electric field around its comer. All the results indicate that the fluorescence of QDs can be efficiently improved by optimizing the parameters of Ag film and Ag cubes.
基金Supported by the National Natural Science Foundation of China（No.61673191）.
文摘Ag nanocubes-reduced graphene oxide（AgNCs-rGO） nanocomposite was successfully prepared by an in situ synthesis method, in which AgNCs were loaded onto the surface of rGO during the formation of AgNCs in an ethylene glycol solution. Characterization by X-ray diffraction, UV-Vis spectroscopy, and scanning electron microscopy indicated the successful preparation of the AgNCs-rGO nanocomposite. Most importantly, the AgNCs-rGO nanocomposite exhibited excellent electrocatalytic activity for the reduction of H2O2, leading to a high-performance non-enzymatic H2O2 sensor with a linear detection range and detection limit of approximately 0.1 mmol/L to 70 mmol/L（r=0.999） and 0.58 μmol/L, respectively. Our present work provides a new and highly efficient method for fabricating high-performance electrochemical sensors.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51272246 and 81172082)the Fundamental Research Funds for the Central Universities,China(Grant No.2030000001)
文摘Gold （Au） nanocage@SiO2 nanoparticles are prepared by a novel approach. The silver （Ag） nanocube@SiO2 structure is synthetized firstly. Next, the method of etching a SiO2 shell by boiling water is adopted to change the penetration rate of AuCl4- through the SiO2 shell. AuCl4- can penetrate through silica shells of different thickness values to react with the Ag nanocube core by changing the incubation time. The surface plasma resonance （SPR） peak of synthetic Au nanocage@SiO2 can be easily tuned into the near-infrared region. Besides, CdTeS quantum dots （QDs） are successfully connected to the surface of Au nanocage@SiO2, which testifies that the incubation process does not change the property of silica.
文摘Surface-enhanced Raman spectroscopy （SERS） is a fast analytical technique for trace chemicals; however, it requires the active SERS-substrates to adsorb analytes, thus limiting target species to those with the desired affinity for substrates. Here we present networked polyacrylic acid sodium salt （PAAS） film entrapped Ag-nanocubes （denoted as Ag-nanocubes@PAAS） as an effective SERS-substrate for analytes with and without high affinity. Once the analyte aqueous solution is cast on the dry Ag-nanocubes@PAAS substrate, the bibulous PAAS becomes swollen forcing the Ag-nanocubes loose, while the analytes diffuse in the interstices among the Ag-nanocubes. When dried, the PAAS shrinks and pulls the Ag-nanocubes back to their previous aggregated state, while the PAAS network ＂detains＂ the analytes in the small gaps between the Ag-nanocubes for SERS detection. The strategy has been proven effective for not only single- analytes but also multi-analytes without strong affinity for Ag, showing its potential in SERS-based simultaneous multi-analyte detection of both adsorbable and non-adsorbable pollutants in the environment.
基金supported by the National Natural Science the Foundations of China(Nos.11774171,11374159)the Fundamental Research Funds for the Central Universities(Nos.NJ20160105,NZ2015101)sponsored by Qing Lan Project of Jiangsu Province
文摘The controllable synthesis of uniform silver nanocubes with high purity is pivotal for the fundamental study of self-assembly and further research on the hollow nanostructures,gold nanocages for instance.Here,Ag nanocubes of different sizes were synthesized by an improved polyol method.With addition of HCl solution,Ag nanocubes with size about 100 nm were obtained under an air atmosphere.And Ag nanocubes with size around50 nm can be produced in a short time under Argon atmosphere with the presence of NaHS instead of HCl.Meanwhile,uniform Ag nanocubes with size larger than 100 nm were also synthesized successfully via adjusting experiment parameters.Results of transmission electron microscopy(TEM)combined with selected area electron diffraction(SAED)show that the Ag nanocubes are single crystalline with six(200)surface plane.In the UV-Vis-NIR optical absorption spectrum,the diple moment resonance absorption peak is changed in the range of 420—500nm with the increase of Ag nanocubes size.
