Immobilization of β-Galactosidase onto Functionalized Graphene Nano-sheets Using Response Surface Methodology and Its Analytical Applications
Open Access
- 18 July 2012
- journal article
- research article
- Published by Public Library of Science (PLoS) in PLOS ONE
- Vol. 7 (7) , e40708
Abstract
β-Galactosidase is a vital enzyme with diverse application in molecular biology and industries. It was covalently attached onto functionalized graphene nano-sheets for various analytical applications based on lactose reduction. Response surface methodology based on Box-Behnken design of experiment was used for determination of optimal immobilization conditions, which resulted in 84.2% immobilization efficiency. Native and immobilized functionalized graphene was characterized with the help of transmission and scanning electron microscopy, followed by Fourier transform infrared (FTIR) spectroscopy. Functionalized graphene sheets decorated with islands of immobilized enzyme were evidently visualized under both transmission and scanning electron microscopy after immobilization. FTIR spectra provided insight on various chemical interactions and bonding, involved during and after immobilization. Optimum temperature and energy of activation (Ea) remains unchanged whereas optimum pH and Km were changed after immobilization. Increased thermal stability of enzyme was observed after conjugating the enzyme with functionalized graphene. Immobilized β-galactosidase showed excellent reusability with a retention of more than 92% enzymatic activity after 10 reuses and an ideal performance at broad ranges of industrial environment.Keywords
This publication has 43 references indexed in Scilit:
- Purification and In Situ Immobilization of Papain with Aqueous Two-Phase SystemPLOS ONE, 2010
- Biocompatibility of Graphene OxideDiscover Nano, 2010
- Lactose nano-probe optimized using response surface methodologyBiosensors and Bioelectronics, 2009
- The chemistry of graphene oxideChemical Society Reviews, 2009
- Optimal immobilization of β-galactosidase from Pea (PsBGAL) onto Sephadex and chitosan beads using response surface methodology and its applicationsBioresource Technology, 2009
- Box-Behnken design: An alternative for the optimization of analytical methodsAnalytica Chimica Acta, 2007
- Single Sheet Functionalized Graphene by Oxidation and Thermal Expansion of GraphiteChemistry of Materials, 2007
- The rise of grapheneNature Materials, 2007
- Galacto-oligosaccharide synthesis by immobilized Aspergillus oryzae β-galactosidaseFood Chemistry, 2006
- A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein-dye bindingAnalytical Biochemistry, 1976