title: Magnetic single-enzyme nanoparticles with high activity and stability.
abstract: Magnetic single-enzyme nanoparticles (SENs) encapsulated within a composite inorganic/organic polymer network were fabricated via the surface modification and in situ aqueous polymerization of separate enzyme molecule. The resultant nanoparticles were characterized by transmission electron microscope (TEM), Fourier transform infrared (FTIR) spectrometer and X-ray diffraction (XRD). These particles are almost spherical in shape and have a unique size of about 50 nm in diameter. Electrical and magnetic measurements reveal that the magnetic SENs have a conductivity of 2.7 x 10(-3)Scm(-1), and are superparamagnetic with a saturation magnetization of 14.5e microg(-1) and a coercive force of 60Oe. Compared with free enzyme, encapsulated enzyme exhibits a strong tolerance to the variation of solution pH, high temperature, organic solvent and long-term storage, thus showing significantly enhanced enzyme performance and stability.
authors.affiliation: College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China.
authors.forename: Zhengpeng
authors.initials: Z
authors.lastname: Yang
authors.forename: Shihui
authors.initials: S
authors.lastname: Si
authors.forename: Chunjing
authors.initials: C
authors.lastname: Zhang
mesh_terms: D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D004795:Enzyme Stability; D004800:Enzymes, Immobilized / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008280:Magnetics; D046529:Microscopy, Electron, Transmission / Q000379:methods; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology / Q000295:instrumentation / Q000379:methods*; D009930:Organic Chemicals / Q000737:chemistry; D012996:Solutions / Q000737:chemistry; D012997:Solvents / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D013499:Surface Properties; D013696:Temperature; D014961:X-Ray Diffraction / Q000379:methods
chemical_list: D020099:Coated Materials, Biocompatible; D004800:Enzymes, Immobilized; D009930:Organic Chemicals; D012996:Solutions; D012997:Solvents