Design And Performance Research Of Immobilized Laccase With Self-thermal Regulation Function Based On Microencapsulated N-docosane Phase Change Material

Phenolics are a common type of chemical raw materials,often used in pharmaceutical,cosmetics,rubber,paint and other industries.Such substances will pollute the environment and threaten human health,so it is necessary to test them.Although the traditional detection method can accurately determine the content of phenolics,it has the disadvantages of cumbersome steps,long test time,unable to detect in real time and expensive.As a new type of phenolics detection equipment,laccase sensor has the advantages of small size,high sensitivity,real-time detection,simple detection and relatively low price.It is a type of detection equipment that is easy to popularize.However,the poor stability of the laccase protein has led to problems such as short service life,poor resistance to high temperatures,and a narrow applicable temperature range.Related research shows that the laccase sensor prepared by immobilized laccase has better detection performance,higher stability and longer service life than the laccase sensor prepared by directly attaching laccase to the electrode surface.On this basis,a new type of laccase immobilization system is designed in this paper,which introduces phase change material with self-thermal regulation function into the laccase carrier to improve the temperature resistance and temperature stability of immobilized laccase,thereby improving the ability of the laccase sensor to withstand high temperature and broadening the test temperature conditions of the laccase sensor.In the preparation process,according to the optimal activity temperature of immobilized laccase is 45?,use n-docosane with a phase change temperature of 44.5? as the phase change core material,use a high bio-affinity polydopamine/silica multi-layer shell to coat the phase change material to microencapsulate it.The multi-layer shell material avoids the leakage of the phase change material during the melting process and improves the thermal conductivity and specific surface area of the material;Furthermore,loading gold nanoparticles on the surface of the shell material to increase the binding site of laccase on the surface of the microcapsules,and at the same time improve its electrochemical performance to a certain extent;Finally,modify the surface of the modified microcapsules with a layer of copper ions,and the laccase is immobilized by the immobilized metal-chelated affinity chromatography method to obtain the immobilized laccase with self-thermal regulation performance.The results show that the immobilized laccase prepared in this experiment has good reusability and storage stability.Moreover,compared with free laccase,the heat resistance and temperature stability of immobilized laccase containing phase change materials have been improved to a certain extent.Therefore,it is foreseeable that the tolerance of the laccase sensor prepared by immobilized laccase to high temperature and the temperature range applicable in the test will be improved to a certain extent,making the laccase sensor in the field of phenolics detection get more widely used.