Construction And Application Of Novel Cu-Based Artificial Metal Mimetic Enzymes

Bio-enzymatic catalysis has attracted the attention of researchers because it is highly efficient,specific,and green catalyst.It has a good application prospect in the fields of food,medicine and industrial catalysis.However,in practical applications,bio-enzymes have the disadvantages of high production costs,low yields,easy denaturation and inactivation in extreme environment,and inability to be reused,which greatly limits their application.Mimetic enzymes(artificial enzymes)with low-cost and high-activity have emerged,effectively overcoming the shortcomings of biological enzymes.Artificial enzymes are designed and synthesized with simpler molecules based on the characteristics of natural enzymes,but they also have high efficiency and specificity like enzymes.Laccase is a copper-containing polyphenol oxidase,acting on a variety of phenols and aniline substances,and can be used to degrade organic contaminants.However,there are still relatively few studies on laccase mimics.Therefore,this topic is devoted to the search for a novel copper-containing artificial metalloenzyme,and applied to the detection and degradation of phenols and aniline pollutants.Through the investigation of the structure,enzyme-like activity and stability of the artificial metal enzyme,the performance of laccase mimic was evaluated and its value in practical application was explored.The main work is carried out as follows:1.The use of guanosine-5'-monophosphate disodium salt(GMP)and Cu2+coordination self-assembly to form a novel copper-containing mimic enzyme(Cu/GMP),which can catalyze the oxidation of 2,4-dichlorophenol and 4-aminoantipyrine to generate red products and can simulate laccase applied to a variety of phenolic compounds,proving that Cu/GMP possesses highly efficient and stable laccase-like activity and can be used for the detection of phenolic compounds.2.A simple,quick and sensitive method of adrenaline detection was established.Both Cu/GMP and laccase can catalyze the oxidation of epinephrine to produce chromogenic substances with UV absorbance at 418 nm to determine the concentration of epinephrine.Kinetic experiments showed that Cu/GMP has much high substrate affinity for epinephrine,and the maximum reaction rate is 40 times higher than that of laccase.The detection limit for epinephrine is 0.41 ?g/mL,which is about 16-fold more than laccase(6.67 ?g)in detection sensitivity,which will be of great significance for applications in the field of epinephrine detection.3.A novel magnetic artificial metal simulating laccase(Fe3O4@Cu/GMP)was constructed,and the magnetic Fe304 nanoparticles were embedded in the Cu/GMP coordination polymer.The stability of Fe3O4@Cu/GMP was studied.The results showed that the biomimetic enzyme was much more stable than the natural laccase in extreme environments such as low pH,high temperature,and high salt concentration.Compared to the reusability of Cu/GMP,that of magnetic bionic enzymes can be effectively improved.After repeated use 5 times,it still remains more than 70%of the catalytic activity.