Silver Nanoparticles Prepared With Small Molecules As Stabilizers And Their Analytical Applications

With the development of science and technology and the rapid development of nanotechnology,noble metal nanoclusters are one of the hot spots in the field of nanomaterials research.Gold nanoclusters and silver nanoclusters have attracted much attention in the field of precious metals because of their good biocompatibility,high quantum yield and excellent optical stability.Because of their excellent performance,they play a pivotal role in biological detection,environmental detection,chemical analysis,electronic detection and other fields.Water-soluble silver nanoclusters are prepared by the stabilization of silver atoms in aqueous solution with a suitable stabilizer.In this paper,two small molecular dyes,eosin Y and nucleosin,were used as stabilizers to prepare silver nanoclusters successfully,which were used to detect vinegar and surfactants.In addition,two methods of preparing silver nanoparticles were also studied.Similarly,the successfully prepared silver nanoparticles were used to detect actual water samples and drugs.Specific experimental contents are described as follows:（1）Using eosin Y as stabilizer and Na BH₄ as reducing agent,silver nanoclusters with maximum excitation wavelength of 480 nm and emission wavelength of 520 nm were successfully prepared.The silver nanoclusters prepared by this method have a strong fluorescence,and the fluorescence intensity of the silver nanoclusters will be affected by p H,so the linear relationship between the fluorescence intensity of the silver nanoclusters and p H was explored.In the range of p H 2.36～5.02,the fluorescence intensity of the silver nanoclusters quenched significantly with the decrease of p H value,and the fluorescence intensity（I_F）of the silver nanoclusters had a good linear relationship with p H value.Based on this relationship,the p H of vinegar was tested and analyzed,and the results were satisfactory.On the basis of this experiment,a simple and rapid method for measuring p H of solution was established.（2）Silver nanoclusters were successfully prepared by reduction method using nucleustin as stabilizer.The maximum excitation wavelength and emission wavelength of the silver nanoclusters prepared by this method are 370 nm and 500 nm,respectively.It is found that cetyltrimethylammonium bromide（CTAB）has a great influence on the silver light intensity of the silver nanoclusters.The linear relationship between the fluorescence intensity of the silver nanoclusters and the concentration of cetyltrimethylammonium bromide（CTAB）was investigated.When the concentration of CTAB was in the range of 0.01-1μmol/L,the decrease of fluorescence of silver nanoclusters showed a good linear relationship with it,and the detection limit was 6.1×10^-9 mol/L.Therefore,we established a simple and fast method for detecting CTAB.（3）A kind of silver nanoparticles with strong scattering was successfully prepared by using newly prepared ascorbic acid as reducing agent and silver ammonia solution as silver source.When the silver nanoparticles prepared by this method are diluted 100 times,the resonance light scattering intensity at 547 nm is the highest.It is found that hydrogen sulfide has a great influence on the resonance light scattering intensity of the silver nanoparticles.Therefore,the linear relationship between hydrogen sulfide concentration and the change value of the resonance light scattering intensity of the silver nanoparticles is explored.When the concentration of hydrogen sulfide is in the range of 1.5-3.5μmol/L,the resonance light scattering intensity of silver nanoparticles shows a good linear relationship with it,and the detection limit is 0.15μmol/L.Based on this linear relationship,it can be used to detect the content of hydrogen sulfide in actual water samples.（4）Large size silver nanoparticles were successfully prepared by using Mucobromic acid as both stabilizer and reducer.The silver nanoparticles prepared by this method have strong scattering at 467nm.The scattering intensity of silver nanoparticles is greatly affected by glutathione.The linear relationship between the concentration of glutathione and the scattering intensity of the silver nanoparticles was investigated.When the concentration of glutathione was in the range of 0.5-7.5μmol/L,the scattering degree of the silver nanoparticles showed a good linear relationship,and the detection limit was 9.5×10^-8 mol/L.Based on this,a sensitive and accurate method for the determination of glutathione in glutathione tablets was established successfully.