title: Electrostatic immobilization of glucose oxidase in a weak acid, polyelectrolyte hyperbranched ultrathin film on gold: fabrication, characterization, and enzymatic activity.
abstract: In this paper we show that hyperbranched polymers can be used as a host matrix for electrostatic entrapment of enzymes. Specifically, amine-functionalized glucose oxidase (GOx+) and horseradish peroxidase, as well as poly(amidoamine) dendrimer-modified horseradish peroxidase, reversibly sorb into polyanionic, hyperbranched poly(sodium acrylate) (PAA-) films that are on the order of a few hundred angstroms thick. The quantity of GOx+ entrapped within the PAA- films depends on the nature of film preparation but is typically on the order of 0.06 unit/cm2. The extent to which entrapped GOx+ retains its activity depends on the film history, but for PAA-/GOx+ composites not exposed to glucose and stored at 4 degrees C, the original activity is retained for up to 68 days and perhaps longer.
authors.affiliation: Department of Chemistry, Texas A&M University, College Station 77842-3012, USA.
authors.forename: J G
authors.initials: JG
authors.lastname: Franchina
authors.forename: W M
authors.initials: WM
authors.lastname: Lackowski
authors.forename: D L
authors.initials: DL
authors.lastname: Dermody
authors.forename: R M
authors.initials: RM
authors.lastname: Crooks
authors.forename: D E
authors.initials: DE
authors.lastname: Bergbreiter
authors.forename: K
authors.initials: K
authors.lastname: Sirkar
authors.forename: R J
authors.initials: RJ
authors.lastname: Russell
authors.forename: M V
authors.initials: MV
authors.lastname: Pishko
mesh_terms: D000179:Acrylates / Q000737:chemistry; D001896:Boron Compounds / Q000737:chemistry; D002021:Buffers; D004800:Enzymes, Immobilized / Q000737:chemistry* / Q000378:metabolism*; D005949:Glucose Oxidase / Q000737:chemistry* / Q000378:metabolism*; D006046:Gold / Q000737:chemistry*; D006735:Horseradish Peroxidase / Q000737:chemistry / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D013058:Mass Spectrometry / Q000379:methods; D011108:Polymers / Q000737:chemistry; D013050:Spectrometry, Fluorescence; D017550:Spectroscopy, Fourier Transform Infrared; D055672:Static Electricity
chemical_list: C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D000179:Acrylates; D001896:Boron Compounds; D002021:Buffers; D004800:Enzymes, Immobilized; D011108:Polymers; D006046:Gold; D005949:Glucose Oxidase; D006735:Horseradish Peroxidase