Prussian Blue Nanoparticles Peroxidase Enzyme And Simulation Application In Hydrogen Peroxide And Glucose Detection

The application of nanomaterials as the candidates of peroxidase mimetics has recently been of great interest since the work of Yan et al. on intrinsic peroxidase-like activity of Fe3O4magnetic nanoparticles (NPs). Following their work, some other nanomaterials, including gold NPs, FeS nano-sheet, CeFe2O4magnetic NPs, CuO NPs, Co3O4NPs, V2O5nanowires, carbon nanomaterials, and RuO2NPs have been discovered to possess intrinsic peroxidase-like activity. The nanomaterials as the peroxidase mimetics have the advantages of low cost, ease of preparation and high stability compared to HRP.Prussian blue, Fe4[Fe(CN)6]3, has been extensively explored as electron transfer mediator for the construction of first-generation oxidase-based electrochemical biosensor due to its excellent electrochemical behavior and good catalytic property. Prussian blue contains Fe2+/Fe3+redox couple, the reversible conversion of which occurs in the reaction centers of a number of peroxidase enzymes. More recently the peroxidase-like activity of γ-Fe2O3magnetic NPs was reported to improve significantly after modification with Prussian blue. However, Prussian blue has not been determined to be a potential peroxidase mimetics. We here demonstrate for the first time that Prussian blue NPs (PB NPs) exhibit intrinsic peroxidase-like activity like HRP. And the PB NPs were successfully used as peroxidase mimetics for colorimetric and chemiluminescence detection of H2O2and glucose.Prussian blue nanoparticles as peroxidase mimetic for colorimetric detection of H2O2and glucosePrussian blue nanoparticles can catalyze H2O2-mediated oxidation of classical peroxidase substrate2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) to produce a green colored product. The catalysis follows Michaelis-Menen kinetics and shows strong affinity for H2O2. Using PB NPs as a peroxidase mimetics, a colorimetric method was developed for the detection of5.0×10-8-5.0×10-5mol L-1HO2, with a detection limit of3.1×10-8mol L-1. When the catalytic reaction of PB NPs was coupled with the glucose catalytic reaction by glucose oxidase (GOx), a sensitive and selective colorimetric method for the detection of glucose was realized. The limit of detection for glucose was determined to be as low as3×10-8mol L-1, with a linear range from1.0×10-7mol L-1to5.0×10-5mol L-1. Compared with other nanomaterials-based peroxidase mimetics, PB NPs provides10-100times higher sensitivity toward the detection of H2O2and glucose.Prussian blue nanoparticles as peroxidase mimetic for chemiluminescence detection of H2O2and glucosePrussian blue nanoparticles were found to have strong catalytic effect on the chemiluminescence oxidation of luminol with H2O2in alkaline conditions. The experimental variables, including PB NPs concentration, luminol concentration, flow rate, and sampling volume, were thoroughly investigated with a flow injection mode. Under the optimum conditions, the relative chemiluminescence intensity was linearly related to the concentration of H2O2in the range of5.0×10-8-1.0×10-4mol L"1with a detection limit of1.8×10-8mol L-1. By immobilizing glucose oxidase on the inner wall of the glass tube and connecting into the flow system, glucose can on-line convert into H2O2and detect by present chemiluminescence system. The linear range for glucose was in the range of1.0×10-7～1.0x10-4mol L-1. The detection limit was7.2×10-8mol L-1glucose.The detection platform developed showed great potential applications in varieties of physiological importance substances when merged with appropriate H2O2-produc-ing oxidases.