title: Hierarchical porous TiO2 fabricated from magnolia grandiflora petals templates for the immobilization and electrical wiring of proteins.
abstract: Hierarchical porous titanium dioxide (hp-TiO2) was prepared using natural magnolia grandiflora petals as templates and was further employed for the immobilization of horseradish peroxidase (HRP). Scanning electron microscopy (SEM) and nitrogen adsorption-desorption measurement revealed the wrinkled and porous structure of the obtained hp-TiO2. Fourier transform infrared spectroscopy (FT-IR) indicated the effective immobilization and conformation retention of HRP on hp-TiO2. HRP immobilized on hp-TiO2 exhibited direct, reversible, and surface-controlled redox reaction with the electron transfer rate constant of 5.46 s(-1). Furthermore, the immobilized HRP exhibited a wide linear detection range from 1.0 to 524.0 µM. The detection limit, based on a signal-to-noise ratio of 3, was down to 0.87 µM. The apparent Michaelis-Menten constant (Km(app)) of the immobilized HRP was 0.223 mM. In addition, the sensor possessed appreciable repeatability, reproducibility and remarkable stability for the sensitive determination of H2O2. Thus, this kind of hp-TiO2 can be used as an attractive material for immobilizing proteins and constructing biosensors.
authors.affiliation: College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, China. Electronic address: xuqin@yzu.edu.cn.
authors.forename: Qin
authors.initials: Q
authors.lastname: Xu
authors.affiliation: College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, China.
authors.forename: Jiaqian
authors.initials: J
authors.lastname: Tang
authors.affiliation: College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Shen
authors.affiliation: College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, China.
authors.forename: Longyun
authors.initials: L
authors.lastname: Jin
authors.affiliation: College of Chemistry and Chemical Engineering, Yangzhou University, Yangzhou 225002, China. Electronic address: xyhu@yzu.edu.cn.
authors.forename: Xiaoya
authors.initials: X
authors.lastname: Hu
mesh_terms: D000327:Adsorption; D015374:Biosensing Techniques; D004563:Electrochemistry; D004800:Enzymes, Immobilized / Q000737:chemistry*; D035264:Flowers; D006418:Heme / Q000737:chemistry; D006735:Horseradish Peroxidase / Q000737:chemistry; D031566:Magnolia; D036103:Nanotechnology / Q000379:methods*; D009584:Nitrogen / Q000737:chemistry; D016062:Porosity; D014025:Titanium / Q000737:chemistry*
chemical_list: D004800:Enzymes, Immobilized; C009495:titanium dioxide; D006418:Heme; D014025:Titanium; D006735:Horseradish Peroxidase; D009584:Nitrogen
keywords: Direct electron transfer; Hierarchical porous; Horseradish peroxidase; Immobilization; TiO(2)