title: Integrated electrochemical biosensor based on algal metabolism for water toxicity analysis.
abstract: An autonomous electrochemical biosensor with three electrodes integrated on the same silicon chip dedicated to the detection of herbicides in water was fabricated by means of silicon-based microfabrication technology. Platinum (Pt), platinum black (Pt Bl), tungsten/tungsten oxide (W/WO3) and iridium oxide (Pt/IrO2) working ultramicroelectrodes were developed. Ag/AgCl and Pt electrodes were used as reference and counter-integrated electrodes respectively. Physical vapor deposition (PVD) and electrodeposition were used for thin film deposition. The ultramicroelectrodes were employed for the detection of O2, H2O2 and pH related ions H3O(+)/OH(-), species taking part in photosynthetic and metabolic activities of algae. By measuring the variations in consumption-production rates of these electroactive species by algae, the quantity of herbicides present at trace level in the solution can be estimated. Fabricated ultramicroelectrodes were electrochemically characterized and calibrated. Pt Black ultramicroelectrodes exhibited the greatest sensitivity regarding O2 and H2O2 detection while Pt/IrO2 ultramicroelectrodes were more sensitive for pH measurement compared to W/WO3 ultramicroelectrodes for pH measurement. Bioassays were then conducted to detect traces of Diuron herbicide in water samples by evaluating disturbances in photosynthetic and metabolic activities of algae caused by this herbicide.
authors.affiliation: CNRS, LAAS, 7 avenue du colonel Roche, F-31400 Toulouse, France; Université de Toulouse, UPS, LAAS, F-31400 Toulouse, France.
authors.forename: A
authors.initials: A
authors.lastname: Tsopela
authors.affiliation: CNRS, LAAS, 7 avenue du colonel Roche, F-31400 Toulouse, France; Université de Toulouse, UPS, LAAS, F-31400 Toulouse, France.
authors.forename: A
authors.initials: A
authors.lastname: Lale
authors.affiliation: CNRS, LAAS, 7 avenue du colonel Roche, F-31400 Toulouse, France; Université de Toulouse, UPS, LAAS, F-31400 Toulouse, France.
authors.forename: E
authors.initials: E
authors.lastname: Vanhove
authors.affiliation: Université de Toulouse, UPS, LGC, 31062 Toulouse, France.
authors.forename: O
authors.initials: O
authors.lastname: Reynes
authors.affiliation: CNRS, LAAS, 7 avenue du colonel Roche, F-31400 Toulouse, France; Université de Toulouse, UPS, LAAS, F-31400 Toulouse, France.
authors.forename: I
authors.initials: I
authors.lastname: Séguy
authors.affiliation: CNRS, LAAS, 7 avenue du colonel Roche, F-31400 Toulouse, France; Université de Toulouse, UPS, LAAS, F-31400 Toulouse, France.
authors.forename: P
authors.initials: P
authors.lastname: Temple-Boyer
authors.affiliation: Université du Québec à Montréal, 201 Président Kennedy, Montréal, Canada.
authors.forename: P
authors.initials: P
authors.lastname: Juneau
authors.affiliation: Université du Québec à Montréal, 201 Président Kennedy, Montréal, Canada.
authors.forename: R
authors.initials: R
authors.lastname: Izquierdo
authors.affiliation: CNRS, LAAS, 7 avenue du colonel Roche, F-31400 Toulouse, France; Université de Toulouse, UPS, LAAS, F-31400 Toulouse, France.
authors.forename: J
authors.initials: J
authors.lastname: Launay
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D016825:Chlamydomonas reinhardtii / Q000378:metabolism*; D004237:Diuron / Q000032:analysis* / Q000378:metabolism; D055664:Electrochemical Techniques / Q000295:instrumentation*; D004867:Equipment Design; D006540:Herbicides / Q000032:analysis* / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000032:analysis / Q000378:metabolism; D057230:Limit of Detection; D008839:Microelectrodes; D010100:Oxygen / Q000032:analysis / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000378:metabolism
chemical_list: D006540:Herbicides; D014874:Water Pollutants, Chemical; D004237:Diuron; D006861:Hydrogen Peroxide; D010100:Oxygen
keywords: Algal metabolism; Hydrogen peroxide; Oxygen; Pesticides detection; Ultramicroelectrodes; pH measurement