title: Microalgae dual-head biosensors for selective detection of herbicides with fiber-optic luminescent O2 transduction.
abstract: The microalgal species Dictyosphaerium chlorelloides (D. c.) was immobilized into porous silicone films and their photosynthetic activity was monitored with an integrated robust luminescent O2 sensor. The biosensor specificity towards a particular pesticide has been achieved by manufacturing a fiber-optic dual-head device containing both analyte-sensitive and analyte-resistant D. c. strains. The latter are not genetically modified microalgae, but a product of modified Luria-Delbrück fluctuation analysis followed by ratchet selection cycles. In this way the target herbicide decreases the O2 production of the analyte-sensitive immobilized strain without affecting the analyte-resistant population response; any other pollutant will lower the O2 production of both strains. The effect of the sample flow-rate, exposure time to the herbicide, biomass loading, biosensor film thickness, intensity of the actinic light, illumination cycle, and temperature on the biosensor response has been evaluated using waterborne simazine as test bench. The biosensing device is able to provide in situ measurements of the herbicide concentration every 180 min. The biosensor limit of detection for this herbicide was 12 μg L(-1), with a working range of 50-800 μg L(-1). The biosensor specificity to simazine has been assessed by comparing its response to that of isoproturon.
authors: Chemical Optosensors and Applied Photochemistry Group (GSOLFA), Dpmt. of Organic Chemistry, Faculty of Chemistry, Complutense University of Madrid, E-28040 Madrid, Spain.
authors: David
authors: D
authors: Haigh-Flórez
authors: Microalgae Biotechnology: Production and Toxicity Group (ALBIOTOX), Dpmt. of Animal Production (Genetics), Faculty of Veterinary Medicine, Complutense University of Madrid, E-28040 Madrid, Spain.
authors: Cristina
authors: C
authors: de la Hera
authors: Microalgae Biotechnology: Production and Toxicity Group (ALBIOTOX), Dpmt. of Animal Production (Genetics), Faculty of Veterinary Medicine, Complutense University of Madrid, E-28040 Madrid, Spain.
authors: Eduardo
authors: E
authors: Costas
authors: Chemical Optosensors and Applied Photochemistry Group (GSOLFA), Dpmt. of Organic Chemistry, Faculty of Chemistry, Complutense University of Madrid, E-28040 Madrid, Spain. Electronic address: orellana@quim.ucm.es.
authors: Guillermo
authors: G
authors: Orellana
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D018914:Cells, Immobilized / Q000166:cytology / Q000378:metabolism; D004867:Equipment Design; D005336:Fiber Optic Technology / Q000295:instrumentation*; D006540:Herbicides / Q000032:analysis* / Q000378:metabolism; D057230:Limit of Detection; D049449:Luminescence; D058086:Microalgae / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D012839:Simazine / Q000032:analysis* / Q000378:metabolism; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000378:metabolism
chemical_list: D006540:Herbicides; D014874:Water Pollutants, Chemical; D010100:Oxygen; D012839:Simazine
keywords: Dictyosphaerium chlorelloides; Luminescence; Microalgae; Optical biosensor; Simazine