title: Amperometric hydrogen peroxide biosensor with sol-gel/chitosan network-like film as immobilization matrix.
abstract: A new type of sol-gel/organic hybrid composite material based on the cross-linking of natural polymer chitosan with (3-aoryloxypropyl) dimethoxymethylsilane was developed for the fabrication of an amperometric H(2)O(2) biosensor. The composite film was used to immobilize horseradish peroxidase (HRP) on a gold disk electrode. The properties of sol-gel/chitosan and sol-gel/chitosan-HRP films have been carefully characterized by atomic force microscopy and Fourier transform infrared. By using fluorescent label, a protein density on sol-gel/chitosan has been calculated to be 3.14 x 10(12) moleculescm(-2). With the aid of catechol mediator, the biosensor had a fast response of less than 2 s with linear range of 5.0 x 10(-9)-1.0 x 10(-7) mol l(-1) and a detection limit of 2 x 10(-9) mol l(-1). Its current response shows a typical Michaelis-Menten mechanism. The apparent Michaelis-Menten constant K(M)(app) is found to be 1.30 micromol l(-1). The activation energy for enzymatic reaction is calculated to be 8.22 kJ mol(-1). The biosensor retained approximately 75% of its original activity after about 60 days of storage in a phosphate buffer at 4 degrees C.
authors.affiliation: Lab of Mesoscopic Materials Science, Institute of Analytical Science, Department of Chemistry, Nanjing University, Nanjing 210093, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Wang
authors.forename: Jing-Juan
authors.initials: JJ
authors.lastname: Xu
authors.forename: Hong-Yuan
authors.initials: HY
authors.lastname: Chen
authors.forename: Zu-Hong
authors.initials: ZH
authors.lastname: Lu
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D002686:Chitin / Q000031:analogs & derivatives* / Q000737:chemistry*; D048271:Chitosan; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis; D003460:Crystallization / Q000379:methods*; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004800:Enzymes, Immobilized; D019544:Equipment Failure Analysis; D006735:Horseradish Peroxidase / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000032:analysis* / Q000737:chemistry*; D008567:Membranes, Artificial; D044367:Phase Transition; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
chemical_list: D020099:Coated Materials, Biocompatible; D004800:Enzymes, Immobilized; D008567:Membranes, Artificial; D002686:Chitin; D048271:Chitosan; D006861:Hydrogen Peroxide; D006735:Horseradish Peroxidase