Preparation of porous titania sol-gel matrix for immobilization of horseradish peroxidase by a vapor deposition method.
A new and facile vapor deposition method has been developed for the preparation of sol-gel matrix. This method was used to form a titania sol-gel thin film and to immobilize horseradish peroxidase (HRP) on a glassy carbon electrode surface for the production of an amperometric hydrogen peroxide biosensor. This process prevented the cracking of conventional sol-gel-derived glasses. The morphologies of both titania sol-gel and the enzyme membranes were characterized using scanning electron microscopy and proved to be chemically clean, porous, and homogeneous and to have a very narrow particle size distribution. The sol-gel-derived titania-modified electrode retained the enzyme bioactivity and provided for long-term stability of the enzyme in storage. In the presence of catechol as a mediator, the sensor exhibited a rapid electrocatalytic response (less than 5 s), a linear calibration range from 0.08 to 0.56 mM with a detection limit of 1.5 microM and a high sensitivity (61.5 microA mM(-1)) for monitoring of H2O2. Effects of pH and operating potential were also explored for optimum analytical performance by using the amperometric method. The apparent Michaelis-Menten constant of the encapsulated HRP was 1.89 +/- 0.21 mM.
Department of Chemistry, Nanjing University, People's Republic of China.
Jiuhong
J
Yu
Huangxian
H
Ju
D001672:Biocompatible Materials / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D002138:Calibration; D002396:Catechols; D006735:Horseradish Peroxidase / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000032:analysis*; D014025:Titanium / Q000737:chemistry*
D001672:Biocompatible Materials; D002396:Catechols; C009495:titanium dioxide; D006861:Hydrogen Peroxide; D014025:Titanium; D006735:Horseradish Peroxidase