title: Amperometric biosensing systems based on motility and gravitaxis of flagellate algae for aquatic risk assessment.
abstract: Electrochemical biosensing systems for toxic substances were developed on the basis of motility and negative gravitaxis of the unicellular flagellate Chlamydomonas reinhardtii. Changes in the flagellar movement of the flagellates in response to three toxic chemicals, toluene, copper(II) sulfate, and nickel(II) chloride, were monitored as changes in the redox currents for a coexisiting redox marker. The gravitaxis-based flagellate biosensing system was more sensitive to toluene than the motility-based system. A thin-layer flagellate biosensor was also developed. In comparison with the conventional algal biosensors monitoring the photosynthetic activity, the gravitaxis-based thin-layer sensor was more sensitive by more than 1 order of magnitude.
authors.affiliation: Institute of Industrial Science, University of Tokyo, Komaba, Meguro-ku, Tokyo 153-8505, Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Shitanda
authors.forename: Kazutake
authors.initials: K
authors.lastname: Takada
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Sakai
authors.forename: Tetsu
authors.initials: T
authors.lastname: Tatsuma
mesh_terms: D000818:Animals; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D016825:Chlamydomonas reinhardtii / Q000187:drug effects / Q000502:physiology*; D019327:Copper Sulfate / Q000737:chemistry; D004563:Electrochemistry; D004784:Environmental Monitoring; D005407:Flagella / Q000187:drug effects / Q000502:physiology; D006112:Gravitation; D009043:Motor Activity / Q000187:drug effects / Q000502:physiology*; D009532:Nickel / Q000737:chemistry; D010084:Oxidation-Reduction; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D013997:Time Factors; D014050:Toluene / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D014050:Toluene; C022838:nickel chloride; D009532:Nickel; D019327:Copper Sulfate