Consulta: creatorFacets:"Lehaitre, Michel"
Registros recuperados: 12
Data/hora: 01/06/2024 10:40:00

Toward in situ detection of algae species
Provedor de dados: 5
Autores: Colas, Florent; Laurent, Sebastien; Lehaitre, Michel; Hamelin, Muriel; Crassous, Marie-pierre; Antoine, Elisabeth; Dreanno, Catherine; Deuff, Albert; Compere, Chantal.
For the last few years there is a more and more pressing need to develop system for detecting HAB at their early stage. Researchers have then been working on new in situ sensor. In this paper a submarine transducer based on surface plasmon resonance is reported. It demonstrated a refractive index resolution of 3.10(-6), which is promising for later phytoplankton detection.
Tipo: Text
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00107/21802/20328.pdf

Effects of a sewage plume on the biology, optical characteristics, and particle size distributions of coastal waters
Provedor de dados: 5
Autores: Petrenko, Aa; Jones, Bh; Dickey, Td; Lehaitre, Michel; Moore, C.
The effect of a sewage plume on the biology, optical characteristics, and particle size distributions of coastal waters was evaluated around the Sand Island, Hawaii, outfall diffuser. In situ physical and biooptical data and Niskin bottle samples were collected during a 1-week cruise from September 25 to October 1, 1994. One or two layers affected by sewage could be distinguished in the water column: recently discharged (''new'') sewage plume waters and ''old'' plume waters. In conditions characterized by high Froude number the distribution of chlorophyll fluorescence in new plume waters was the same as for ambient waters, while for low Froude number, chlorophyll fluorescence increased within the plume, demonstrating the importance of physical forcing on...
Tipo: Text
Ano: 1997
URL: http://archimer.ifremer.fr/doc/00335/44647/57346.pdf

Biofouling protection for marine environmental sensors
Provedor de dados: 5
Autores: Delauney, Laurent; Compere, Chantal; Lehaitre, Michel.
These days, many marine autonomous environment monitoring networks are set up in the world. These systems take advantage of existing superstructures such as offshore platforms, lightships, piers, breakwaters or are placed on specially designed buoys or underwater oceanographic structures. These systems commonly use various sensors to measure parameters such as dissolved oxygen, turbidity, conductivity, pH or fluorescence. Emphasis has to be put on the long term quality of measurements, yet sensors may face very short-term biofouling effects. Biofouling can disrupt the quality of the measurements, sometimes in less than a week. Many techniques to prevent biofouling on instrumentation are listed and studied by researchers and manufacturers. Very few of them...
Tipo: Text
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00008/11920/8626.pdf

Toward Detection of Harmful Algae Blooms by in situ Surface Plasmon Resonance Spectroscopy
Provedor de dados: 5
Autores: Laurent, Sebastien; Colas, Florent; Hamelin, Muriel; Crassous, Marie-pierre; Antoine, Elisabeth; Lehaitre, Michel; Compere, Chantal.
Among marine algae species, Alexandrium minutum produces a phycotoxin called paralytic shellfish poisoning (PSP) that is introduced in the food chain through the ingestion of phytoplankton by shellfishs, and later by human consumers. Thus, in situ monitoring of A. minutum proliferation in coastal seawater is of great economical importance for marine resources exploitation. Here, we propose a rapid test for the detection of A. minutum by surface plasmon resonance spectroscopy. First, whole genomic DNA is extracted from the algae. Second, a 677 bp long portion of the 28S ribosomal DNA is amplified by PCR. Third, the PCR product is detected by surface plasmon resonance spectroscopy onto a DNA functionalized gold substrate.
Tipo: Text
Palavras-chave: PCR; Algal detection; In situ; Spectroscopy; Surface plasmon resonance.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6830.pdf

Detection of polycyclic aromatic hydrocarbon (PAH) compounds in artificial sea-water using surface-enhanced Raman scattering (SERS)
Provedor de dados: 5
Autores: Peron, Olivier; Rinnert, Emmanuel; Lehaitre, Michel; Crassous, Philippe; Compere, Chantal.
This paper reports an accurate synthesis of surface-enhanced Raman scattering (SERS) active substrates, based on gold colloidal monolayer, suitable for in situ environmental analysis. Quartz substrates were functionalized by silanization with (3-mercaptopropyl)trimethoxysilane (MPMS) or (3-aminopropyl)trimethoxysilane (APTMS) and they subsequently reacted with colloidal suspension of gold metal nanoparticles: respectively, the functional groups SH and NH2 bound gold nanoparticles. Gold nanoparticles were prepared by the chemical reduction of HAuCl4 using sodium tricitrate and immobilized onto silanized quartz substrates. Active substrate surface morphology was characterized with scanning electron microscopy (SEM) measurements and gold nanoparticles...
Tipo: Text
Palavras-chave: Sensor; Sea water; PAH detection; SERS; Silanization; Gold nanoparticles.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6616.pdf

Biofouling protection for marine underwater observatories sensors
Provedor de dados: 5
Autores: Delauney, Laurent; Compere, Chantal; Lehaitre, Michel.
These days, many marine autonomous environment monitoring networks are set up in the world. Such systems take advantage of existing superstructures such as offshore platforms, lightships, piers, breakwaters or are placed on specially designed buoys or deep sea fix stations. The major goal for these equipments is to provide in real time reliable measurements without costly frequent maintenance. These autonomous monitoring systems are affected by a well known phenomena in seawater condition which is biofouling. Consequently, such system without efficient biofouling protection is hopeless. This protection must be applied to the sensors and to the underwater acoustic communication equipments.
Tipo: Text
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00107/21801/20176.pdf

Surface plasmon resonance in chalcogenide glass-based optical system
Provedor de dados: 5
Autores: Le Person, Jenny; Colas, Florent; Compere, Chantal; Lehaitre, Michel; Anne, M; Boussard Pledel, C; Bureau, B; Adam, J; Deputier, S; Guilloux Viry, M.
The surface plasmon resonance phenomenon has been studied in a chalcogenide glass-based optical system. IR transmission properties of these materials combined to their high refractive indices lead to advantageous properties for sensing. In this study, numerical simulations have been carried out to investigate the potentialities of sulfide glass from the GeGaSbS system as a coupling prism material. Then, an angular modulation SPR biosensor has been set up in the Kretschmann-Raether arrangement. Experimental data are consistent with numerical calculation and the detection limit of the sensor is 3 x 10(-5) RIU. These preliminary results are promising. Further investigations have to be carried out to confirm the great potentialities of those materials for...
Tipo: Text
Palavras-chave: Infrared; Biosensor; Surface plasmon resonance; Chalcogenide glass.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/2008/publication-3955.pdf

Biosensors for the detection and monitoring of Alexandrium minutum along the French coasts
Provedor de dados: 5
Autores: Antoine, Elisabeth; Compere, Chantal; Cosnier, Serge; Crassous, Marie-pierre; Derbal, Hassina; Erard-le Denn, Evelyne; Gondran, Chantal; Guilminot, Elodie; Lehaitre, Michel; Mazeas, Florence; Moreau, Hervé; Perrot, Hubert; Pradier, Claire-marie; Salmain, Michèle.
The microalgae Alexandrium minutum produces neurotoxins responsible for paralytic shellfish poisoning, which upon accumulation in shellfish represent a human health risk. This species recurrently forms toxic blooms in the Northern part of the French Brittany coast. At present, algae identification relies on tedious microscope observations mostly performed by skilled taxonomists in laboratories. Newly emerging fields of molecular taxonomy, nanoscale technology and biotechnology offer opportunities for the development of in-situ biosensors for the detection and the monitoring of toxic algae.
Tipo: Text
Ano: 2003
URL: http://archimer.ifremer.fr/doc/00089/19986/17650.pdf

First Steps of in Situ Surface-Enhanced Raman Scattering During Shipboard Experiments
Provedor de dados: 5
Autores: Peron, Olivier; Rinnert, Emmanuel; Colas, Florent; Lehaitre, Michel; Compere, Chantal.
It is shown that the surface-enhanced Raman scattering (SERS) technique can be applied to detect organic molecules during in situ experiments. To this purpose, we used trans-1,2-bis(4-pyridyl)ethylene (BPE) as a target molecule. Adsorbed on the SERS chemosensor surface and excited under laser, the vibration modes of the molecules can be identified. SERS chemosensors are based on quartz substrates functionalized by silanization and partially coated with gold nanoparticles. SERS measurements during shipboard experiments were made with a home-made in situ Raman spectrometer connected to a marinized micro-fluidic system. The device was designed to host chemosensors in order to ensure measurements with a flow cell. A theoretical limit of detection was estimated...
Tipo: Text
Palavras-chave: Surface-enhanced Raman scattering; SERS; Chemosensors; Flow cells; Shipboard experiments; In situ measurements; Freundlich isotherm.
Ano: 2010
URL: http://archimer.ifremer.fr/doc/00016/12691/9718.pdf

IR-biosensor for in situ detection of toxic algae alexandrium minutum
Provedor de dados: 5
Autores: Le Person, Jenny; Compere, Chantal; Lehaitre, Michel; Anne, Marie-laure; Boussard-pledel, Catherine; Bureau, Bruno; Adam, Jean-luc; Guilloux-viry, M; Burel, L.
Toxic algal blooms are a public health issue and constitute a menace for coastal areas. The potentiality of a chalcogenide optical fibre biosensor, operating in the mid-infrared (MIR) spectral domain, is studied. In order to monitor blooms of toxic algae, more specifically Alexandrium minutum specie, two ways are explored: immuno-biosensing and DNA identification.
Tipo: Text
Ano: 2005
URL: http://archimer.ifremer.fr/doc/00089/19993/17656.pdf

Towards in situ detection of PAH trace in sea-water using SERS-active sensors
Provedor de dados: 5
Autores: Peron, Olivier; Rinnert, Emmanuel; Lehaitre, Michel; Colas, Florent; Compere, Chantal.
This paper reports the development of a sensor based on surface-enhanced Raman scattering (SERS) for analyses in sea-water. Polycyclic aromatic hydrocarbons (PAHs) are targeted by these sensors and their detection in situ summons up chemical synthesis and optical development. Firstly, a relevant synthesis of SERS active substrates based on gold nanostructures is presented. Different kinds of substrates have been synthesized under variable experimental conditions to modify some parameters such as i) gold shape, size and distribution and such as ii) chemical functionalization: (i) gold nanoparticles were prepared either by chemical reduction of HAuCl4 or by physical deposition. (ii) Substrates were functionalized by hydrophobic films to allow nonpolar...
Tipo: Text
Palavras-chave: Functionalization; Silanization; Gold nanostructures; SERS; PAH detection; Sea-water; Sensor; In situ.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/00012/12363/9152.pdf

A new device for in situ video and fluorescence analysis of marine particles. Applications to phytoplankton studies.
Provedor de dados: 5
Autores: Lunven, Michel; Lehaitre, Michel; Nascimben, Eric; Rouvillain, Julien; Berric, Roger; Le Gall, Erwan; Gentien, Patrick.
A new video-microscope has been developed for in situ investigation on marine particles. A field of view is produced by a laser beam at 473 nm. Individual cells or particles that entered this field of view appear as individual diffraction-limited spots of light, which are resolved from the dark background. A mobile high-pass optical filter (610 nm) can be controlled and displaced in front of the CCD camera, allowing simultaneously imaging and discrimination between fluorescing and non-fluorescing particles. We have the possibility to add a band pass filter for phycoerytrin detection. The system allows white light visualisation of particles ranging from 10 µm to several millimetres, depending on the zoom magnification. With the 610 nm high pass filter, the...
Tipo: Text
Palavras-chave: Surveillance; Phytoplancton; Phycotoxine.
Ano: 2005
URL: http://archimer.ifremer.fr/doc/00144/25495/23649.pdf