Visual Detection Of Aflatoxin B1 With Nano Silver And The Composite Particle

At present,nanomaterials are widely understood and used.After the exploration of nanoscale materials,the curiosity of nano silver is increasing,and a new round of exploration is used.In our experiment,instead of the traditional gold nanoparticles,we used the nano silver for visual detection.Compared with nanoscale gold,nano silver is more common in the preparation process,and the cost is relatively low.From the stability,sensitivity and accuracy,there is no difference between the results of the nano gold and the results of the use of nano silver.By following the principle of convenient and quick experiment,nano silver is used as the material of this experiment.In order to improve the stability of silver nanoparticles,we used silica to enhance the stability of silver nanoparticles and form SiO2-AgNPS in the later stage.Nano silver particles were prepared by oxidation-reduction method and observed by transmission electron microscopy(TEM)and ultraviolet visible absorption spectroscopy(UV Vis)for the structure morphology of silver nanoparticles prepared each time.By determining the best concentration of Sodium Chloride Solution and the optimum concentration of aptamers,the designed system can reach the most stable state,then the AFB1 is visualized,the standard curve is drawn according to the peak absorption peak,and the authenticity is tested by the recovery experiment,and the detection limit is finally obtained.In order to enhance the stability of nano silver particles,this experiment is to use SiO2-AgNPs Composite particle to test the experiment,and choose the particle form of nanometer silver particles to wrap silica.The combination of the composite particles is mainly through chemical coupling or physical methods.The composition of the detection system is consistent with the use of the nano silver particle system.After the feasibility test is carried out by the recovery experiment,the detection limit of the system is finally obtained.According to the experimental results,it is found that the nano silver particles prepared by the redox method after the reagents ratio have been greatly improved in terms of the size and distribution.The volume of nano silver and composite particles in the two systems designed in this experiment is 250 ?L,the volume of the 0.4 ?L aptamer solution is 60 ?L,the volume of NaCl solution of 0.15M is 60?L the volume of Aspergillus flavus B1 is 60?L,and the total volume is 430p,L After calculation,the detection limit of nano silver detection system is LOD=11.761 ng/L.SiO2-AgNPS was used to carry out the above experiments,and the final detection limit was LOD = 10.984 ng/L.The two systems increase the visual inspection line from 4?g/L to 300ng/L,the detection effecct has been improved.