title: Fe3O4 peroxidase mimetics as a general strategy for the fluorescent detection of H2O2-involved systems.
abstract: Enzyme mimetics have recently attracted considerable interest because of their high stability and low cost. We developed a general H2O2-involved fluorescence system using Fe3O4 magnetic microspheres as peroxidase mimetics and benzoic acid (BA) as indicator. Glucose and p-nitrophenol were used as models to determine the characteristics and effectiveness of the system. Glucose oxidase hydrolyzes glucose, in the presence of oxygen, to H2O2 followed by the activation of Fe3O4 MMs, resulting in the catalyzed oxidation of benzoic acid. Glucose can be determined by the quantitative fluorescence production. p-Nitrophenol is determined as model compounds which competes with benzoic acid for H2O2 resulting in the decreased catalytic oxidation of benzoic acid with the Fe3O4 MMs. The detection limit of the Fe3O4/H2O2/BA system is 0.008 μM for H2O2, 0.025 μM for glucose and 0.05 μM for p-nitrophenol. Furthermore, the system had high sensitivity, good selectivity and was capable of sensing glucose in human serum and p-nitrophenol in water samples. The proposed system has great potential in the chemical/biological sensing of a variety of analytes associated with reactions that produce or consume H2O2.
authors.affiliation: College of Science, Beijing Key Laboratory of Environmentally Harmful Chemical Analysis, Beijing University of Chemical Technology, Beijing 100029, PR China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Shi
authors.affiliation: College of Science, Beijing Key Laboratory of Environmentally Harmful Chemical Analysis, Beijing University of Chemical Technology, Beijing 100029, PR China.
authors.forename: Ping
authors.initials: P
authors.lastname: Su
authors.affiliation: College of Science, Beijing Key Laboratory of Environmentally Harmful Chemical Analysis, Beijing University of Chemical Technology, Beijing 100029, PR China.
authors.forename: Yingying
authors.initials: Y
authors.lastname: Wang
authors.affiliation: College of Science, Beijing Key Laboratory of Environmentally Harmful Chemical Analysis, Beijing University of Chemical Technology, Beijing 100029, PR China. Electronic address: yangyi@mail.buct.edu.cn.
authors.forename: Yi
authors.initials: Y
authors.lastname: Yang
mesh_terms: D015374:Biosensing Techniques; D001786:Blood Glucose / Q000032:analysis*; D003124:Colorimetry; D005290:Ferric Compounds / Q000737:chemistry*; D006801:Humans; D006861:Hydrogen Peroxide / Q000032:analysis*; D057230:Limit of Detection; D053768:Metal Nanoparticles / Q000737:chemistry*; D018716:Molecular Mimicry; D009596:Nitrophenols / Q000032:analysis*; D009195:Peroxidase / Q000737:chemistry*; D014877:Water Pollution, Chemical / Q000032:analysis*
chemical_list: D001786:Blood Glucose; D005290:Ferric Compounds; D009596:Nitrophenols; C000499:ferric oxide; D006861:Hydrogen Peroxide; D009195:Peroxidase; C024836:4-nitrophenol
keywords: Fe(3)O(4) magnetic microsphere; General system; Glucose; Hydrogen peroxide; Peroxidase mimetic; p-Nitrophenol