A novel method for preparing silver nanoelectrode ensembles (SNEEs) and gold nanoelectrode ensembles (GNEEs) has been developed. Silver colloid particles were first absorbed to the gold electrode surface to form a mo...A novel method for preparing silver nanoelectrode ensembles (SNEEs) and gold nanoelectrode ensembles (GNEEs) has been developed. Silver colloid particles were first absorbed to the gold electrode surface to form a monolayer silver colloid. N-hexadecyl mercaptan was then assembled on the electrode to form a thiol monolayer on which hydrophilic ions cannot be transfered. The SNEEs was prepared by removing thiol from silver colloid surface through applying an AC voltage with increasing frequency at 0.20 V (vs. SCE). Finally, GNEEs was obtained by immersing a SNEEs into 6 mol/L HNO3 to remove the silver colloid particles. By comparison with other methods such as template method etc., this method enjoys some advantages of lower resistance, same diameter, easy preparation, controllable size and density.展开更多
In this study,a convenient method of preparing the substrate is proposed with one-pot synthesis of silver colloid under body heat,and the SERS detection uses the fresh substrate to avoid the drawback of substrates’sh...In this study,a convenient method of preparing the substrate is proposed with one-pot synthesis of silver colloid under body heat,and the SERS detection uses the fresh substrate to avoid the drawback of substrates’short life of use.The synthesis of silver colloid is carried out in a 10 mL vial by using ascorbic acid as a reductant and trisodium citrate as a stabilizer.The vial is grasped with the palm of the experimenter for several minutes without shaking.The proposed method is simple,rapid,green energy and cost-effective.By adjusting the concentration of trisodium citrate,not only the particle size can be controlled from about 110 nm to 50 nm but also the homogeneity of nanoparticles can be improved.As a SERS substrate,the silver colloid has high batch reproducibility and showed good SERS activity.The relative standard deviation between different manufacturers is 5.51%when the substrate of silver colloid is used for the detection of rhodamine 6 G.Using the substrate,the lowest detection concentrations of rhodamine 6 G,crystal violet,enrofloxacin,melamine and leucomalachite green are 1.0×10-8,6.1×10-8,1.4×10-6,7.1×10-5 and 5.1×10-8 mol/L,respectively.Results demonstrate that the developed method has the advantage of convenience and high efficiency in the field preparation of reliable SERS substrate.展开更多
The effect of solvent on surface enhanced Raman scattering [SERS) of colloidal silver has been studied. Experiments show that the intensity of SERS is related to the polarity and molecular constitution of the solvent....The effect of solvent on surface enhanced Raman scattering [SERS) of colloidal silver has been studied. Experiments show that the intensity of SERS is related to the polarity and molecular constitution of the solvent. The influence of solvent is due to the change of the adsorption quantity and adsorption intensity.展开更多
The highly ordered silver-coated colloidal crystals arrays and macroporous silver films were derived through an electrostatics-induced adsorption effect using polystyrene(PS) as templates. Carboxyl-modified PS microsp...The highly ordered silver-coated colloidal crystals arrays and macroporous silver films were derived through an electrostatics-induced adsorption effect using polystyrene(PS) as templates. Carboxyl-modified PS microspheres were prepared by emulsifier-free emulsion polymerization using methacrylic acid(MAA) as the functional monomer. PS microspheres were self-assembled into close packing colloidal crystals of facecentered cubic arrays to the substrate with vertical deposition method. These colloidal crystals were modified using dopamine(DA) to form poly-dopamine(PDA) during its oxidative polymerization. Through electrostatic interaction, the silver nanoparticles were deposited and adsorbed onto the surfaces of colloidal crystals templates by exposing [Ag(NH_3)_2]^+solution to infrared irradiation. Removal of the polymeric template by etching with methylbenzene solvent resulted in 3D ordered macroporous silver films. The structural and properties of the ordered silver-coated arrays and macroporous silver films were characterized by field emission scanning electron microscopy(FE-SEM), X-ray diffraction(XRD), UV-vis spectroscopy and surface-enhanced Raman spectroscopy(SERS). The results indicate that the prepared silver-coated arrays and macroporous silver films possess the features of ordered multilayer arrangement, uniformity and repeatability as well as an ideal SERS effect.展开更多
The paper shows the results of method development identification of colloidal silver nanoparticles on the components of the Raman spectra, using the conditions information uncertainty decision to increase the reliabil...The paper shows the results of method development identification of colloidal silver nanoparticles on the components of the Raman spectra, using the conditions information uncertainty decision to increase the reliability evaluating the presence nanoparticles at the surface polyester fibers.展开更多
文摘A novel method for preparing silver nanoelectrode ensembles (SNEEs) and gold nanoelectrode ensembles (GNEEs) has been developed. Silver colloid particles were first absorbed to the gold electrode surface to form a monolayer silver colloid. N-hexadecyl mercaptan was then assembled on the electrode to form a thiol monolayer on which hydrophilic ions cannot be transfered. The SNEEs was prepared by removing thiol from silver colloid surface through applying an AC voltage with increasing frequency at 0.20 V (vs. SCE). Finally, GNEEs was obtained by immersing a SNEEs into 6 mol/L HNO3 to remove the silver colloid particles. By comparison with other methods such as template method etc., this method enjoys some advantages of lower resistance, same diameter, easy preparation, controllable size and density.
文摘In this study,a convenient method of preparing the substrate is proposed with one-pot synthesis of silver colloid under body heat,and the SERS detection uses the fresh substrate to avoid the drawback of substrates’short life of use.The synthesis of silver colloid is carried out in a 10 mL vial by using ascorbic acid as a reductant and trisodium citrate as a stabilizer.The vial is grasped with the palm of the experimenter for several minutes without shaking.The proposed method is simple,rapid,green energy and cost-effective.By adjusting the concentration of trisodium citrate,not only the particle size can be controlled from about 110 nm to 50 nm but also the homogeneity of nanoparticles can be improved.As a SERS substrate,the silver colloid has high batch reproducibility and showed good SERS activity.The relative standard deviation between different manufacturers is 5.51%when the substrate of silver colloid is used for the detection of rhodamine 6 G.Using the substrate,the lowest detection concentrations of rhodamine 6 G,crystal violet,enrofloxacin,melamine and leucomalachite green are 1.0×10-8,6.1×10-8,1.4×10-6,7.1×10-5 and 5.1×10-8 mol/L,respectively.Results demonstrate that the developed method has the advantage of convenience and high efficiency in the field preparation of reliable SERS substrate.
文摘The effect of solvent on surface enhanced Raman scattering [SERS) of colloidal silver has been studied. Experiments show that the intensity of SERS is related to the polarity and molecular constitution of the solvent. The influence of solvent is due to the change of the adsorption quantity and adsorption intensity.
基金supported by the National Natural Science Foundation of China (Grant Nos. 50873085 and 21375116)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)
文摘The highly ordered silver-coated colloidal crystals arrays and macroporous silver films were derived through an electrostatics-induced adsorption effect using polystyrene(PS) as templates. Carboxyl-modified PS microspheres were prepared by emulsifier-free emulsion polymerization using methacrylic acid(MAA) as the functional monomer. PS microspheres were self-assembled into close packing colloidal crystals of facecentered cubic arrays to the substrate with vertical deposition method. These colloidal crystals were modified using dopamine(DA) to form poly-dopamine(PDA) during its oxidative polymerization. Through electrostatic interaction, the silver nanoparticles were deposited and adsorbed onto the surfaces of colloidal crystals templates by exposing [Ag(NH_3)_2]^+solution to infrared irradiation. Removal of the polymeric template by etching with methylbenzene solvent resulted in 3D ordered macroporous silver films. The structural and properties of the ordered silver-coated arrays and macroporous silver films were characterized by field emission scanning electron microscopy(FE-SEM), X-ray diffraction(XRD), UV-vis spectroscopy and surface-enhanced Raman spectroscopy(SERS). The results indicate that the prepared silver-coated arrays and macroporous silver films possess the features of ordered multilayer arrangement, uniformity and repeatability as well as an ideal SERS effect.
文摘The paper shows the results of method development identification of colloidal silver nanoparticles on the components of the Raman spectra, using the conditions information uncertainty decision to increase the reliability evaluating the presence nanoparticles at the surface polyester fibers.
