The Enzyme-like Activity Of LaCoO₃ And LaCoO₃-SBA-15 And Their Application In Biodetection

Natural enzymes can catalyze biochemical reactions efficiently and specifically.They can be widely used in medicine,chemistry,agriculture and other fields.However,since most enzymes are proteins,they are easily inactivated and expensive because it is difficult to purify.The nanomaterials artificial enzymes can overcome the disadvantages of native enzymes such as poor stability,inactivation in extreme conditions,difficulty in preparation and purification,high cost of obtaining,and difficult to control its catalytic ability.Therefore,in recent years,the study of enzymes-like activity of nanomaterials has become a research hotspot.Based on this,we investigated the enzyme-mimic activity of LaCoO₃ and LaCoO₃-SBA-15 and its application in glucose and dopamine detection.?1?Perovskite materials LaCoO₃ were prepared by citric acid sol-gel method,and characterized by SEM,XRD,XPS,FT-IR.The LCO NPs can catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine?TMB?in the presence of H2O2 generating a color change in acid conditions or decompose the H2O2 in alkaline conditions with the generation of oxygen.Catalytic kinetics together with the possible mechanism of the peroxidase-like activity was investigated.The peroxidase-like catalytic property of LaCoO₃ nanoparticles was found to originate from its ability of the acceleration of electron transfer.Kinetic analysis shows the LaCoO₃ NPs can catalyze the TMB oxidation with a high Vmax and good affinity towards the TMB.Then based on its peroxidase property,LaCoO₃ NPs were applied to determine the dopamine by using colorimetric method and the linear range,the detection limit?LOD?and selectivity of dopamine sensing were discussd.The standard addition experiments were further performed with recoveries between 98.65% and 99.73%,and all the relative standard deviations?RSDs?were below 4.0%.So the above method can be applied to the determination of dopamine accurately as an efficient method.?2?LaCoO₃-SBA-15 composite were prepared by sol-gel method and characterized by XRD,SEM,FT-IR,TEM,N2 adsorption-desorption.The LaCoO₃-SBA-15 nanomaterials were found to possess both peroxidase-like and catalase-like catalytic activities and the effect of pH,temperature on these enzyme mimic activities were discussed.Catalytic kinetics of the peroxidase-like activity was investigated.Kinetic analysis shows the LaCoO₃-SBA-15 NPs can catalyze the TMB oxidation with a high Vmax,which imply the high performance of the synthesized material for peroxidase-like activity.Then based on its peroxidase property,LaCoO₃-SBA-15 NPs were applied to determine the glucose in human serum by using colorimetric method.The linear range of dopamine sensing was found out to be 0 m M-2.5 mM and the detection limit?LOD?was 0.03 mM.The standard addition experiments were further performed with recoveries between 98.2% and 103.3%,and all the relative standard deviations?RSDs?were below 2.0%.The determination of glucose therefore showed high accuracy,good selectivity and has potential for practical application.