Research On The Toxicity Of ZnO Nanoparticles On The Respiration And Photosynthesis Of Aloe

ZnO nanomaterials have a broad application perspective,but along with its benefits to mankind,it brings some adverse effects.Therefore,it is very important to study the potential toxicity of ZnO nanoparticles to living things.In this thesis,Aloe Barbadensis Mill was the experimental object,and the ZnO nanoparticles was prepared by sol-gel method.The slices of aloe leaves were treated with culture media containing ZnO nanoparticles for 15 hours,and then the changes of dissolved oxygen concentration with time in aloe culture medium was measured by Oxi7310 dissolved oxygen meter.We can obtain the change rate of dissolved oxygen concentration,which was proportional to the rate of respiration and net photosynthesis.By analyzing the change rate of the dissolved oxygen concentration in the culture medium,the effect of ZnO nanoparticles on the respiration and photosynthesis of aloe can be analyzed.In the study of the effects of ZnO nanoparticles on the respiration of aloe,ZnO nanoparticles were added to the culture medium with concentrations of 0 mg/L,50 mg/L,100 mg/L,200 mg/L,respectively.The 0 mg/L was used as control.The total surface area of the aloe leaf slices was about 60 cm~2,and in the whole process of the experiment,the BOD bottles should be sealed and kept in dark place.The corresponding change rate of dissolved oxygen from aloe treated with various concentrations of ZnO nanoparticles was-21.86 mg/(L·h),-18.28 mg/(L·h),-15.14 mg/(L·h)and-12.89 mg/(L·h).This showed that the ZnO nanoparticles with different concentrations inhibited the respiration of aloe and the toxicity of ZnO nanoparticles to aloe increased with the increase of the concentration of ZnO nanoparticles.In the study of the effect of ZnO nanoparticles on the photosynthesis of aloe,ZnO nanoparticles were added to the culture medium with concentrations of 0 mg/L,50 mg/L,100 mg/L,200 mg/L,respectively.The 0 mg/L was used as control.The total surface area of the aloe leaf slices was about 60 cm~2,and the whole experiment was carried out under stable light source,the photon flux density was 750±30 ?mol/m2/s.The corresponding change rate of dissolved oxygen from aloe treated with various concentrations of ZnO nanoparticles was 52.59 mg/(L·h),44.95 mg/(L·h),40.77 mg/(L·h)and 35.64 mg/(L·h).This showed that the ZnO nanoparticles with different concentrations inhibited the photosynthesis of aloe and the toxicity of ZnO nanoparticles to aloe increased with the increase of the concentration of ZnO nanoparticles.As a conclusion,ZnO nanoparticles could inhibit the respiration and photosynthesis of aloe,but the cause of this inhibition still needs further research in the future.