| Noble metal nanoparticles are widely used in medical and catalytic fields due to their catalytic and surface plasmon resonance absorption properties.Especially when the nanoparticles are arranged in order,the structure of dense hexagons will produce relatively uniform distribution of "hot spots",presenting a specific optical resonance phenomenon,enhancing the surface to enhance the Raman scattering effect.Therefore,large-area ordered nanostructured membranes can be used as the base for SERS detection,which can be applied in rapid trace detection and environmental detection.In this paper,two kinds of gold nanoparticles were prepared by potassium sodium tartrate reduction method,ascorbic acid as reducing agent and trisodium citrate as coating agent,and the preparation process was improved to obtain gold nanoparticles with good monodispersity.LB plating method was used to prepare orderly arranged gold nanostructured films,and the experimental conditions were explored.SERS detection was conducted on the prepared gold nanostructured films and the effect in application was analyzed.The main contents and results are as follows:(1)With sodium potassium tartrate reduction preparation of nanometer gold particles,adjust temperature of experiments to explore,through comparing the different under the condition of preparation of nanometer gold colloid ultraviolet absorption spectra and TEM topography,found that when the introduction of 0.04 m L of 0.1 mol/L silver nitrate reagent,the preparation of nanometer gold particles monodispersity,best best particle morphology.The heating temperature should be more than 90? and the heating time should be less than 2 hours.When the seed content is 4m L and 8m L,the effect is the best.Uv-vis spectrum analysis shows that gold nanoparticles with smaller particle size have strong catalytic effect in practical application.(2)Gold nanoparticles prepared with trisodium citrate as the coating agent and ascorbic acid as the reducing agent were found to have strong monodispersity without the introduction of other reagents.Since the growth solution mixed with trisodium citrate and ascorbic acid has strong reducibility,it can also react at room temperature.So the experiments prove that the heating temperature control at 60? above can get the uniform morphology of gold nanoparticles,and because the sodium citrate has protective effect,the preparation of nanometer gold colloid is extremely stable,does not exist because of the heating time is too long or place time is too long and cause of precipitation of colloid happen,and proved through the experiment,The heating time has no significant influence on the experimental results.In order to facilitate the experimental operation,the heating time is generally controlled at about 1 hour.In the process of growth,due to the insufficient amount of growth liquid or gold precursor,it is easy to cause the phenomenon of single nucleation or uneven growth of particles.After experimental verification,8m L seed solution can be used in the process of growth.The gold nanoparticles prepared by this method are ready for the preparation of large area ordered gold structure films.(3)It was found that the modification effect of n-octanethiol was stronger than ndodecyl mercaptan in the preparation of gold nanostructured films.On average,1m L PVP with a concentration of 0.100mol/L,250?L ODT with a concentration of0.01mol/L,and 1% PEG reagent diluted 1000 times per 80 m L colloidal solution were added.0.010 m L is the best.In the process of surface modification,the dosage of ethanol reagent was determined to be 20 m L,and the dosage of chloroform reagent was1.000 m L for re-dispersion.When SERS detection was carried out on CV,the membrane showed good homogeneity,and low concentration of melamine molecules could be quickly detected when melamine was detected. |
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