Modulation Of Nanozymes Catalytic Activity And Its Application In Analysis And Sensing

Nanozymes have attracted extensive research attention owing to their high stability against denaturing,low cost,biocompatibility,as well as their good link with the sensing substrate associated with the sensing signal generation.Therefore,it has been widely utilized in many fields such as biosensing,environmental treatment,disease diagnosis and treatment,antibacterial agents,against biomolecules in the cell,and so on.More importantly,these unique physical and chemical properties not only stimulated them to have tunable catalytic activities,but also provided more possibilities for extensively expanding their chem/biosensing applications.Since most nanozyme-related chemical reactions mainly occur on the surface of nanozymes,surface chemistry-based modulation strategies of nanozymes have been proved to be vital to regulate the catalytic activity of nanozymes.Based on this,this paper mainly focused on the modulation of nanozymes catalytic activities,and linked with the sensing substrate 3,3?,5,5?-tetramethylbenzidine?TMB?for constructing multiple sensing platforms suitable for the detection of life-related molecules and environmental pollutants.1.The paper summarized the classification of nanozymes,the modulation strategies of nanozymes catalytic activity,and the research progress of analytical sensing based on nanozyme-catalyzed substrates TMB.2.A simple strategy for constructing activity-controllable nanozyme is communicated based on the glutathione?GSH?-gated surface chemistry of citrate-capped Pt nanoparticles?Pt NPs?.We found Pt NPs have been shown oxidase-like activity that could effectively catalyze the oxidation of3,3?,5,5?-tertamethylbenzidine?TMB?by O₂,resulting in a typical color change.GSH could regulate the oxidase-like activity of Pt NPs,and finally resulting in the dramatical suppression for the oxidation of TMB by O₂.The addition of copper ions(Cu²⁺)could oxidize GSH into glutathione disulfide?GSSG?,which effectively modulating the oxidase-like activity of Pt NPs and its catalytic reaction of substrate TMB.Furthermore,due to the good fluorescence and photothermal effects associated with the TMB oxidation process,we successfully constructed a three-in-one sensor for Cu²⁺,which based on the integration of colorimetric,photothermal?temperature?and fluorescence signals.3.Through the surface regulation of gold@platinum core-shell nanoparticles?Au@Pt NPs?,we have proposed a synergistic modulation mechanism,and finally achieved the distinct enhancement of peroxidase-like activity of Au@Pt NPs under neutral pH conditions,and successfully constructed a sensing platform for colorimetric and photothermal detection of Pb²⁺.We found that Au@Pt NPs had low catalytic activity at neutral pH conditions,while Tris-HCl?pH 7.0?buffer solution and Pb²⁺could synergistically modulated the peroxidase-like activity of Au@Pt NPs,thus promoting electron transfer between substrates TMB and H₂O₂ with a typical color change.In addition,due to the good photothermal effects associated with the TMB oxidation process,we herein constructed an analytical sensing platform for colorimetric and photothermal detection of Pb²⁺.The strategy not only successfully broke the pH limitation of nanozymes in nanozymes catalysis,but also could be augmented into biological and medical point-of-care testing applications.