Immobilizing cholesterol oxidase in chitosan–alginic acid network

Abstract

Proton conducting biopolymer networks have potential use for bio-sensors. The cost-effective, non-hazardous and environmentally safe biopolymer , such as chitosan, is an attractive feature for bio-sensors. Cholesterol oxidase was immobilized in conducting network via complexation of chitosan with alginic acid . A method for the preparation of the complex along with characterization by elemental analysis , FTIR spectroscopy , TGA and DSC were reported. The proton conductivity chitosan–alginic acid network was studied via impedance spectroscopy under humidified condition. The complex polymer electrolyte with x = 1 exhibited maximum proton conductivity of 1.4 × 10 −3 S/cm at RT, RH ∼ 50%. The potential use of this network in enzyme immobilization was studied by manufacturing cholesterol oxidase entrapped polymer networks . Additionally, the maximum reaction rate ( V max ) and Michaelis–Menten constant ( K m ) were investigated for the immobilized cholesterol oxidase. Also, temperature and pH optimization studies were performed, and operational stability and shelf life of the polymer network were examined.