Construction Of Nano-TiO₂ Artificial Antibody Shell And Its Detection And Degradation Of Chlorpyrifos

In recent years,with the rapid development of science and technology,the environmental pollution problem has become more and more serious,and people’s health has been seriously threatened.The common methods for the detection and degradation of low concentration and high toxicity chlorpyrifos in the environment are chromatography,enzyme inhibition method and immunology method.However,the amount of organic reagents used in the above methods is large,the operation steps are cumbersome and easy to cause pollution.Therefore,it is very important to study the photocatalytic materials with high selectivity,low cost,good stability and no secondary pollution for the detection and degradation of organophosphorus pesticides in agriculture and life.A large number of scientific researchers have been committed to solving this problem.Titanium dioxide has been paid close attention to by a large number of researchers because it can efficiently degrade various pollutants without secondary pollution.In this paper,molecular imprinting technology was innovatively combined with photocatalytic materials to prepare nano-TiO₂ artificial antibody shell material,so that it can not only detect chlorpyrifos specifically but also degrade chlorpyrifos efficiently.In order to improve the utilization rate of light,we doped Fe³⁺and S elements in the nano TiO₂ artificial antibody shell,which increased the spectral absorption range and enhanced the photocatalytic activity.The experimental data show that the preparation of Fe³⁺and S element doped nano TiO₂ artificial antibody shell by sol-gel method not only has the detection function for chlorpyrifos with high toxicity and low concentration,but also can degrade chlorpyrifos efficiently,which has very high research significance.Firstly,the photocatalytic mechanism,the preparation method of core-shell structure,and the basic theory and related applications of artificial antibodies were reviewed.The second is the preparation of chlorpyrifos-imprinted nano-TiO₂ artificial antibody particles and non-imprinted nano-TiO₂ particles,which were characterized by SEM,XRD,IR and kinetic thermodynamics tests.The nano-TiO₂ prepared by SEM morphology observation was particle structure,and the particle size distribution was uneven.XRD pattern showed that the peak was high and sharp,and there was almost no impurity peak,indicating that the crystallinity of nano-TiO₂ particles was high.The grain sizes of the imprinted nano-TiO₂ artificial antibody particles and nano-TiO₂particles were 16.28 nm and 22.98 nm,respectively,calculated by Scherrer formula.Infrared spectrum analysis showed that imprinted TiO₂ nanoparticles were successfully prepared.The chlorpyrifos-imprinted nano-TiO₂ artificial antibody shell and the unimprinted nano-TiO₂ shell were prepared again,and characterized by SEM,XRD,IR and dynamic thermodynamics experiments.The results showed that the particle size of the prepared nano-TiO₂ artificial antibody shell was about 280 nm,and the particle size distribution was uniform.There was almost no impurity peak in the XRD spectrum,and the peak was sharp,indicating that the prepared nano-TiO₂ shell had high crystallinity.The grain sizes of nano-TiO₂ artificial antibody shell and nano-TiO₂ shell were calculated by Scherrer formula as 14.11 nm and 17.66 nm,respectively.The infrared spectrum analysis showed that the nano-TiO₂ artificial antibody shell was successfully prepared.The kinetic thermodynamic experiments showed that the maximum adsorption capacities of imprinted nano-TiO₂ artificial antibody shell and nano-TiO₂ shell were10.58 mg·g^-1 and 7.29 mg·g^-1,respectively,indicating that the imprinted nano-TiO₂artificial antibody shell had greater adsorption capacity.Finally,the imprinted nano-TiO₂ artificial antibody shell doped with Fe³⁺and S elements was prepared and characterized by SEM,XRD,XPS,IR and kinetic thermodynamic tests.The results show that the particle size of the prepared imprinted nano-Fe³⁺/TiO₂ artificial antibody shell and the imprinted nano-S/TiO₂ artificial antibody shell is about 280 nm,and the particle size distribution is uniform.XRD pattern shows that the peak is sharp and there is no impurity peak,indicating that the prepared doped nano-TiO₂ artificial antibody shell has high crystallinity.Further,the grain sizes of the imprinted nano-Fe³⁺/TiO₂ artificial antibody shell and the imprinted nano-S/TiO₂ artificial antibody shell were 18.34 nm and 17.93 nm,respectively,which were larger than those of the undoped nano-TiO₂ artificial antibody shell（14.11 nm）by Scherrer formula.The infrared spectrum and XPS analysis showed that the imprinted nano-Fe³⁺/TiO₂ artificial antibody shell and the imprinted nano-S/TiO₂ artificial antibody shell were successfully prepared.The kinetic thermodynamic experiments showed that the maximum adsorption capacities of the imprinted nano-Fe³⁺/TiO₂artificial antibody shell and the imprinted nano-S/TiO₂ artificial antibody shell were10.01 mg·g^-1 and 9.4 mg·g^-1,respectively,indicating that the doping of Fe³⁺and S had no significant effect on the adsorption performance of the imprinted nano-TiO₂ artificial antibody shell.