title: Development of photocatalytic biosensor for the evaluation of biochemical oxygen demand.
abstract: The photocatalytic biosensor of flow system using semiconductor TiO2 was developed to evaluate biochemical oxygen demand (BOD) levels in river water. Photocatalysis of sample was carried out in a photoreactor with TiO2 and a 6W black-light blue fluorescent tube as light source. Sample from a photoreactor outlet was measured by an oxygen electrode with a biofilm. The sensor response of photocatalytic biosensor was between 5 and 10 min depending on concentration of biochemical in the samples. At BOD of 1 mgl-1, the sensor response increased 1.33-fold in comparison with that without photocatalysis. The degradation of tannic acid and humic acid with photocatalysis were 51.8 and 38.4%, respectively. Gum arabic and linear alkylbenzene sulfonate (LAS) were degraded a little, but gave the responses of more than double to the sensor. Free radicals yielded by photocatalysis in a photoreactor did not affect the sensor response because their lifetime is extremely short. Fairly good correlation (r=0.983) between the sensor method and the conventional method was obtained for test samples. This biosensor using photocatalytic pretreatment improved the sensitivity.
authors.affiliation: Research Center for Advanced Science and Technology, The University of Tokyo, 4-6-1 Komaba Meguro-ku, Tokyo 153-8904, Japan. cheegj@jamstec.go.jp
authors.forename: Gab-Joo
authors.initials: GJ
authors.lastname: Chee
authors.forename: Yoko
authors.initials: Y
authors.lastname: Nomura
authors.forename: Kazunori
authors.initials: K
authors.lastname: Ikebukuro
authors.forename: Isao
authors.initials: I
authors.lastname: Karube
mesh_terms: D018441:Biofilms; D015374:Biosensing Techniques / Q000295:instrumentation*; D002384:Catalysis; D005609:Free Radicals / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000378:metabolism; D010101:Oxygen Consumption / Q000502:physiology*; D010777:Photochemistry; D016958:Pseudomonas putida; D012996:Solutions; D014025:Titanium; D014876:Water Pollution / Q000032:analysis*
chemical_list: D005609:Free Radicals; D012996:Solutions; C009495:titanium dioxide; D006861:Hydrogen Peroxide; D014025:Titanium