Analytical Applications Based On The Regulation Of Enzyme-like Activity Of Au@Pt Nanozymes

Nanozymes are one kind of nanomaterials with nanoscale(1-100 nm)and enzymatic catalytic properties.Compared with natural enzymes,nanozymes have the advantages such as low cost,high stability,good durability and adjustable activity,which have been widely used in industrial,medical and biological fields.However,most nanozymes have the disadvantages of poor specificity and low catalytic activity.Therefore,it is of great significance to investigate the catalytic activity of nanozymes for constructing sensitive and selective analytical sensing platforms.Colorimetric and photothermal methods exhibit good sensing proformance by taking advantages of simple operation,low cost,high sensitivity and good selectivity.Based on the above mentioned,noble metal nanozymes(Au@Pt NPs)with oxidase-like enzyme activity were successfully prepared in this paper.Colorimetric and photothermal sensing platforms based on the regulation of nanozyme catalytic activity were constructed and successfully used for the highly sensitive detection of metal ions.This thesis mainly includes the following contents:1.The recent progress in the classification of nanozymes,the regulation of catalytic activity toward nanozymes and the colorimetric and photothermal methods are introduced.2.We successfully prepared and characterized Au@Pt NPs nanozymes.Further studies have found that the obtained Au@Pt NPs nanozymes can oxidize the specific chromogenic substrate 3,3?,5,5?-tetramethylbenzidine(TMB)into its blue oxidized product(ox TMB)under acidic conditions.However,after the introduction of the target Ag⁺,it shows obvious inhibition toward of Au@Pt NPs nanozymatic activity due to the interaction between the active sites on the material surface and the target.Based on this,we have successfully constructed a simple and highly sensitive sensing platform for colorimetric and photothermal detection of Ag⁺.3.We further found that the Au@Pt NPs nanozymes have selective effects on different metal ions in different p H conditions.Furthermore,different colorimetric and photothermal sensing platforms can be established through the regulation of their nanozymes activity.Under neutral conditions,Au@Pt NPs surface can selectively interact with Hg²⁺and induce obvious aggregation of Au@Pt NPs.The aggregated Au@Pt NPs nanozymes showed higher catalytic activity,and oxidized the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid)ammonium salt(ABTS)into green oxidation state ABTS^·+.Based on this,we successfully constructed a facile and rapid sensitive sensing platform for colorimetric and photothermal detection of Hg²⁺.