title: Using novel polysaccharide-silica hybrid material to construct an amperometric biosensor for hydrogen peroxide.
abstract: A new type of sol-gel organic-inorganic hybrid material was developed and used for the fabrication of an amperometric hydrogen peroxide biosensor. This material was prepared from natural chitosan and recently introduced completely water-soluble precursor, tetrakis(2-hydroxyethyl) orthosilicates (THEOS), by the sol-gel process without the addition of organic solvents and catalysts. The gelation time for the sol-gel transition and dynamic rheological properties of the resultant gel matrix could be modulated by the amount of added THEOS. The structure of the hybrid gel was made up of a network and spherical particles, as confirmed by SEM observation. By electrochemical experiments, it was found that such a hybrid gel matrix could retain the native biocatalytic activity of the entrapped horseradish peroxidase and provide a fast amperometric response to hydrogen peroxide. The linear range for the determination of hydrogen peroxide was found to be from 1.0 x 10(-6) to 2.5 x 10(-4) mol/L with a detection limit of 4.0 x 10(-7) mol/L. The apparent Michaelis-Menten constant was determined to be 2.198 mmol/L. To improve the analytical characteristics of the fabricated biosensor, the effects of applied potential and pH value on the steady-state current were studied. Under the optimized experimental conditions, the fabricated biosensor was found to have good analytical performance, reproducibility, and storage stability.
authors.affiliation: Laboratory for Polymer Composite and Functional Materials, Institute of Optoelectronic and Functional Composite Materials, School of Chemistry and Chemical Engineering, Sun Yat-Sen (Zhongshan) University, Guangzhou 510275, China.
authors.forename: Guan-Hai
authors.initials: GH
authors.lastname: Wang
authors.forename: Li-Ming
authors.initials: LM
authors.lastname: Zhang
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D015374:Biosensing Techniques / Q000295:instrumentation*; D048271:Chitosan / Q000737:chemistry*; D005782:Gels / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000032:analysis* / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D015394:Molecular Structure; D017646:Organosilicon Compounds / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D005782:Gels; D017646:Organosilicon Compounds; D012822:Silicon Dioxide; D048271:Chitosan; D006861:Hydrogen Peroxide