There are an absorption peak at 485 nm and a synchronous fluorescence peak at 510 nm for fluorescein in the medium of 3.4×10 -3 mol/L tri-sodium citrate. The gold nanoparticle system exhibits a characterization r...There are an absorption peak at 485 nm and a synchronous fluorescence peak at 510 nm for fluorescein in the medium of 3.4×10 -3 mol/L tri-sodium citrate. The gold nanoparticle system exhibits a characterization resonance scattering peak at 580 nm. In the coexisting system of gold nanoparticle and fluorescein, there are a synchronous fluorescence peak at 510 nm and a resonance scattering peak at 580 nm. It has been found that the fluorescence peak may be quenched by gold nanoparticle. When the concentration of fluorescein is higher, the A 470 nm affects the I 470 nm of gold nanoparticle. The I 470 nm decreases exponentially with the concentration of fluorescein.展开更多
In basic NH3-NH4Cl buffer solutions,the molecules of complex of some metal（Ⅱ） ions with dithizone can associate one another to produce stable micro-particles,which exhibit resonance photo scattering effect and diff...In basic NH3-NH4Cl buffer solutions,the molecules of complex of some metal（Ⅱ） ions with dithizone can associate one another to produce stable micro-particles,which exhibit resonance photo scattering effect and different color.There is a strongest resonance scattering peak at 605 nm for Zn（Ⅱ）,at 540 nm for Pb（Ⅱ）,at 600 nm for Co（Ⅱ）,at 560 nm for Ni（Ⅱ）,at 560 nm for Cd（Ⅱ）, at 570 nm for Cu（Ⅱ） and at 560 nm for Hg（Ⅱ） in their corresponding particle systems.There is a linear relationship between the scattering intensity and metal ion concentration.Among them,the system of Zn（Ⅱ）-dithizone is most sensitive and is therefore chosen for the determination of Zn concentration in the range of 2.0×10-81.54×(10-6 g/mL),with a detection limit of 8.0×10-9 g/mL.This method has been applied to the determination of microelement Zn in samples with satisfactory sensitivity,simplicity and reproducibility.展开更多
文摘There are an absorption peak at 485 nm and a synchronous fluorescence peak at 510 nm for fluorescein in the medium of 3.4×10 -3 mol/L tri-sodium citrate. The gold nanoparticle system exhibits a characterization resonance scattering peak at 580 nm. In the coexisting system of gold nanoparticle and fluorescein, there are a synchronous fluorescence peak at 510 nm and a resonance scattering peak at 580 nm. It has been found that the fluorescence peak may be quenched by gold nanoparticle. When the concentration of fluorescein is higher, the A 470 nm affects the I 470 nm of gold nanoparticle. The I 470 nm decreases exponentially with the concentration of fluorescein.
文摘In basic NH3-NH4Cl buffer solutions,the molecules of complex of some metal（Ⅱ） ions with dithizone can associate one another to produce stable micro-particles,which exhibit resonance photo scattering effect and different color.There is a strongest resonance scattering peak at 605 nm for Zn（Ⅱ）,at 540 nm for Pb（Ⅱ）,at 600 nm for Co（Ⅱ）,at 560 nm for Ni（Ⅱ）,at 560 nm for Cd（Ⅱ）, at 570 nm for Cu（Ⅱ） and at 560 nm for Hg（Ⅱ） in their corresponding particle systems.There is a linear relationship between the scattering intensity and metal ion concentration.Among them,the system of Zn（Ⅱ）-dithizone is most sensitive and is therefore chosen for the determination of Zn concentration in the range of 2.0×10-81.54×(10-6 g/mL),with a detection limit of 8.0×10-9 g/mL.This method has been applied to the determination of microelement Zn in samples with satisfactory sensitivity,simplicity and reproducibility.
