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Papers by Caroline Montferrand

Research paper thumbnail of Elaboration, caractérisation de nouvelles nanosondes superparamagnetiques pour les immunoessais magnetiques multiparametriques

Http Www Theses Fr, Apr 6, 2012

Ce travail consiste en l’elaboration et l’optimisation de nanobiomarqueurs superparamagnetiques p... more Ce travail consiste en l’elaboration et l’optimisation de nanobiomarqueurs superparamagnetiques pour une technologie innovante, le MIAplex®, developpee par Magnisense pour la detection ultra-sensible de molecules biologiques par immunoanalyse magnetique. Le MIAplex® permet d’evaluer le comportement magnetique a bas champ, en mesurant directement la derivee seconde de l’aimantation. L’obtention d’une signature originale ouvre la perspective de tests multiparametriques. En tant que premiers utilisateurs du MIAplex®, nous commencons ce travail par la mise en place des conditions et parametres de mesure pour une mesure optimale et reproductible. Afin de relier la signature MIAplex® a la mesure conventionnelle de l’aimantation, une etude comparative est realisee. Nous montrons ainsi que la signature MIAplex® correspond a la derivee seconde de l’aimantation SQUID mesuree a bas champ [-15 kA. M-1; 15 kA. M-1] et pour un tres faible pas de mesure (0. 4 kA. M-1). Les courbes experimentales des ferrofluides en systeme dilue sont modelisees avec la fonction de Langevin ponderee par une distribution en taille des nanocristaux. Deux comportements sont observes : dans le cas des nanoparticules de petite taille ou de faible polydispersite, une seule distribution en taille proche de la taille cristalline suffit pour modeliser la courbe d’aimantation bas champ. Pour des nanoparticules de plus grande polydispersite et de taille mediane superieure a 10 nm, les simulations font intervenir des distributions en taille supplementaires. Un modele cœur-coquille permet d’attribuer la population de plus grande taille a l’aimantation du cœur superparamagnetique et la seconde population a l’aimantation plus faible de la coquille. A travers l’etude de l’influence de la composition chimique, de l’etat de surface et de la forme, differents nanomarqueurs sont selectionnes en tant que candidats pour les dosages immunologiques multiparametriques. La derniere partie presente les premiers tests multiparametriques realises avec la technologie MIAplex®. Nous presentons une technologie prometteuse pour le dosage multiparametrique immunologique, basee sur une mesure originale du comportement magnetique a bas champ, que nous relions aux proprietes physico-chimiques des nanoparticules superparamagnetiques.

Research paper thumbnail of SiO2 versus chelating agent@ iron oxide nanoparticles: interactions effect in nanoparticles assemblies at low magnetic field

Journal of Sol-Gel Science and Technology, 2014

Hydrophilic magnetic nanoparticles present many interest for various medical applications due to ... more Hydrophilic magnetic nanoparticles present many interest for various medical applications due to their unique properties: immunoassays, imaging and hyperthermia. With regards to their applicability in the biomedical field, colloidal stability is a key parameter related to nanoparticle surface functionalization. In this paper, we report the water transfer of hydrophobic oleic acid coated iron oxide nanoparticles comparing two methodologies to obtain water dispersible iron oxide nanoparticles: exchange ligands with small strong chelating agent (caffeic acid) and SiO 2 shell passivation. Both strategies are leading to stable aqueous ferrofluid but differing by their interactions. The non linear magnetic behavior at high and low magnetic field and second derivative signature of water dispersed superparamagnetic Fe 3 0 4 nanoparticles samples are studied using conventional SQUID equipment and miniaturized detector MIAplex Ò device. We demonstrated those samples differing only by their interparticle interactions present different magnetic behavior at very low magnetic field whereas at high magnetic field both samples are very similar.

Research paper thumbnail of Effect of Cobalt Doping Concentration on the Crystalline Structure and Magnetic Properties of Monodisperse CoxFe3–xO4 Nanoparticles within Nonpolar and Aqueous Solvents

The Journal of Physical Chemistry C, 2012

Research paper thumbnail of Size-Dependent Nonlinear Weak-Field Magnetic Behavior of Maghemite Nanoparticles

Small, 2012

The magnetic behavior at room temperature of maghemite nanoparticles of variable sizes (from 7 to... more The magnetic behavior at room temperature of maghemite nanoparticles of variable sizes (from 7 to 20 nm) is compared using a conventional super quantum interference device (SQUID) and a recently patented technology, called MIAplex. The SQUID usually measures the magnetic response versus an applied magnetic field in a quasi-static mode until high field values (from -4000 to 4000 kA m(-1)) to determine the field-dependence and saturation magnetization of the sample. The MIAplex is a handheld portable device that measures a signal corresponding to the second derivative of the magnetization around zero field (between -15 and 15 kA m(-1)). In this paper, the magnetic response of the size series is correlated, both in diluted and powder form, between the SQUID and MIAplex. The SQUID curves are measured at room temperature in two magnetic field ranges from -4000 to 4000 kA m(-1) (-5T to 5T) and from -15 to 15 kA m(-1). Nonlinear behavior at weak fields is highlighted and the magnetic curves for diluted solutions evolve from quasi-paramagnetic to superparamagnetic behavior when the size of the nanoparticles increases. For the 7-nm sample, the fit of the magnetization with the Langevin model weighted with log-normal distribution corresponds closely to the magnetic size. This confirms the accuracy of the model of non-interacting superparamagnetic particles with a magnetically frustrated surface layer of about 0.5 nm thickness. For the other samples (10-nm to 21-nm), the experimental weak-field magnetization curves are modeled by more than one population of magnetically responding species. This behavior is consistent with a chemically uniform but magnetically distinct structure composed of a core and a magnetically active nanoparticle canted shell. Accordingly the weak-field signature corresponds to the total assembly of the nanoparticles. The impact of size polydispersity is also discussed.

Research paper thumbnail of Input of Microwaves for Nanocrystal Synthesis and Surface Functionalization Focus on Iron Oxide Nanoparticles

Fundamentals and Applications, 2013

ABSTRACT

Research paper thumbnail of Non-linear magnetic behavior around zero field of an assembly of superparamagnetic nanoparticles

The Analyst, 2012

The MIAplex® device is a miniaturized detector, devoted to the high sensitive detection of superp... more The MIAplex® device is a miniaturized detector, devoted to the high sensitive detection of superparamagnetic nanoprobes for multiparametric immunoassays. It measures a signal corresponding to the second derivative of the magnetization around zero field. Like any new technology, the real success of the MIAplex® detector can only be exploited through a deep understanding of the magnetic signature. In this letter, we study the magnetic behavior around zero-field of diluted lab-made and commercial ferrofluids by comparing together conventional SQUID magnetization and MIAplex® signature.

Research paper thumbnail of Size and polydispersity effect on the magnetization of densely packed magnetic nanoparticles

Journal of Applied Physics, 2012

ABSTRACT The magnetic properties of densely packed magnetic nanoparticles (MNP) assemblies are in... more ABSTRACT The magnetic properties of densely packed magnetic nanoparticles (MNP) assemblies are investigated from Monte Carlo simulations. The case of iron oxide nanoparticles is considered as a typical example of MNP. The main focus is put on particle size and size polydispersity influences on the magnetization curve. The particles are modeled as uniformly magnetized spheres isolated one from each other by a non magnetic layer representing the organic coating. A comparison with recent experimental results on gamma−\gamma-gamma−Fe$_2$O$_3$ powder samples differing by their size is given.

Research paper thumbnail of Iron oxide nanoparticles with sizes, shapes and compositions resulting in different magnetization signatures as potential labels for multiparametric detection

Acta Biomaterialia, 2013

Magnetic iron oxide nanoparticles differing in their size, shape (spherical, hexagonal, rods, cub... more Magnetic iron oxide nanoparticles differing in their size, shape (spherical, hexagonal, rods, cubes) and composition have been synthesized and modified using caffeic acid for transfer to aqueous media and stabilization of the particle suspensions at physiological pH. A super quantum interference device and the recently patented magnetic sensor MIAplex Ò , which registered a signal proportional to the second derivative of the magnetization curve, were used to study the magnetization behavior of the nanoparticles. The differences in the magnetic signatures of the nanoparticles (spheres and rods) make them promising candidates for the simultaneous detection of different types of biological molecules.

Research paper thumbnail of Size-Dependent Nonlinear Weak-Field Magnetic Behavior of Maghemite Nanoparticles

Small, 2012

The magnetic behavior at room temperature of maghemite nanoparticles of variable sizes (from 7 to... more The magnetic behavior at room temperature of maghemite nanoparticles of variable sizes (from 7 to 20 nm) is compared using a conventional super quantum interference device (SQUID) and a recently patented technology, called MIAplex. The SQUID usually measures the magnetic response versus an applied magnetic fi eld in a quasistatic mode until high fi eld values (from -4000 to 4000 kA m − 1 ) to determine the fi eld-dependence and saturation magnetization of the sample. The MIAplex is a handheld portable device that measures a signal corresponding to the second derivative of the magnetization around zero fi eld (between -15 and 15 kA m − 1 ). In this paper, the magnetic response of the size series is correlated, both in diluted and powder form, between the SQUID and MIAplex. The SQUID curves are measured at room temperature in two magnetic fi eld ranges from -4000 to 4000 kA m − 1 (-5T to 5T) and from -15 to 15 kA m − 1 . Nonlinear behavior at weak fi elds is highlighted and the magnetic curves for diluted solutions evolve from quasi-paramagnetic to superparamagnetic behavior when the size of the nanoparticles increases. For the 7-nm sample, the fi t of the magnetization with the Langevin model weighted with log-normal distribution corresponds closely to the magnetic size. This confi rms the accuracy of the model of non-interacting superparamagnetic particles with a magnetically frustrated surface layer of about 0.5 nm thickness. For the other samples (10-nm to 21-nm), the experimental weak-fi eld magnetization curves are modeled by more than one population of magnetically responding species. This behavior is consistent with a chemically uniform but magnetically distinct structure composed of a core and a magnetically active nanoparticle canted shell. Accordingly the weakfi eld signature corresponds to the total assembly of the nanoparticles. The impact of size polydispersity is also discussed.

Research paper thumbnail of Elaboration, caractérisation de nouvelles nanosondes superparamagnetiques pour les immunoessais magnetiques multiparametriques

Http Www Theses Fr, Apr 6, 2012

Ce travail consiste en l’elaboration et l’optimisation de nanobiomarqueurs superparamagnetiques p... more Ce travail consiste en l’elaboration et l’optimisation de nanobiomarqueurs superparamagnetiques pour une technologie innovante, le MIAplex®, developpee par Magnisense pour la detection ultra-sensible de molecules biologiques par immunoanalyse magnetique. Le MIAplex® permet d’evaluer le comportement magnetique a bas champ, en mesurant directement la derivee seconde de l’aimantation. L’obtention d’une signature originale ouvre la perspective de tests multiparametriques. En tant que premiers utilisateurs du MIAplex®, nous commencons ce travail par la mise en place des conditions et parametres de mesure pour une mesure optimale et reproductible. Afin de relier la signature MIAplex® a la mesure conventionnelle de l’aimantation, une etude comparative est realisee. Nous montrons ainsi que la signature MIAplex® correspond a la derivee seconde de l’aimantation SQUID mesuree a bas champ [-15 kA. M-1; 15 kA. M-1] et pour un tres faible pas de mesure (0. 4 kA. M-1). Les courbes experimentales des ferrofluides en systeme dilue sont modelisees avec la fonction de Langevin ponderee par une distribution en taille des nanocristaux. Deux comportements sont observes : dans le cas des nanoparticules de petite taille ou de faible polydispersite, une seule distribution en taille proche de la taille cristalline suffit pour modeliser la courbe d’aimantation bas champ. Pour des nanoparticules de plus grande polydispersite et de taille mediane superieure a 10 nm, les simulations font intervenir des distributions en taille supplementaires. Un modele cœur-coquille permet d’attribuer la population de plus grande taille a l’aimantation du cœur superparamagnetique et la seconde population a l’aimantation plus faible de la coquille. A travers l’etude de l’influence de la composition chimique, de l’etat de surface et de la forme, differents nanomarqueurs sont selectionnes en tant que candidats pour les dosages immunologiques multiparametriques. La derniere partie presente les premiers tests multiparametriques realises avec la technologie MIAplex®. Nous presentons une technologie prometteuse pour le dosage multiparametrique immunologique, basee sur une mesure originale du comportement magnetique a bas champ, que nous relions aux proprietes physico-chimiques des nanoparticules superparamagnetiques.

Research paper thumbnail of SiO2 versus chelating agent@ iron oxide nanoparticles: interactions effect in nanoparticles assemblies at low magnetic field

Journal of Sol-Gel Science and Technology, 2014

Hydrophilic magnetic nanoparticles present many interest for various medical applications due to ... more Hydrophilic magnetic nanoparticles present many interest for various medical applications due to their unique properties: immunoassays, imaging and hyperthermia. With regards to their applicability in the biomedical field, colloidal stability is a key parameter related to nanoparticle surface functionalization. In this paper, we report the water transfer of hydrophobic oleic acid coated iron oxide nanoparticles comparing two methodologies to obtain water dispersible iron oxide nanoparticles: exchange ligands with small strong chelating agent (caffeic acid) and SiO 2 shell passivation. Both strategies are leading to stable aqueous ferrofluid but differing by their interactions. The non linear magnetic behavior at high and low magnetic field and second derivative signature of water dispersed superparamagnetic Fe 3 0 4 nanoparticles samples are studied using conventional SQUID equipment and miniaturized detector MIAplex Ò device. We demonstrated those samples differing only by their interparticle interactions present different magnetic behavior at very low magnetic field whereas at high magnetic field both samples are very similar.

Research paper thumbnail of Effect of Cobalt Doping Concentration on the Crystalline Structure and Magnetic Properties of Monodisperse CoxFe3–xO4 Nanoparticles within Nonpolar and Aqueous Solvents

The Journal of Physical Chemistry C, 2012

Research paper thumbnail of Size-Dependent Nonlinear Weak-Field Magnetic Behavior of Maghemite Nanoparticles

Small, 2012

The magnetic behavior at room temperature of maghemite nanoparticles of variable sizes (from 7 to... more The magnetic behavior at room temperature of maghemite nanoparticles of variable sizes (from 7 to 20 nm) is compared using a conventional super quantum interference device (SQUID) and a recently patented technology, called MIAplex. The SQUID usually measures the magnetic response versus an applied magnetic field in a quasi-static mode until high field values (from -4000 to 4000 kA m(-1)) to determine the field-dependence and saturation magnetization of the sample. The MIAplex is a handheld portable device that measures a signal corresponding to the second derivative of the magnetization around zero field (between -15 and 15 kA m(-1)). In this paper, the magnetic response of the size series is correlated, both in diluted and powder form, between the SQUID and MIAplex. The SQUID curves are measured at room temperature in two magnetic field ranges from -4000 to 4000 kA m(-1) (-5T to 5T) and from -15 to 15 kA m(-1). Nonlinear behavior at weak fields is highlighted and the magnetic curves for diluted solutions evolve from quasi-paramagnetic to superparamagnetic behavior when the size of the nanoparticles increases. For the 7-nm sample, the fit of the magnetization with the Langevin model weighted with log-normal distribution corresponds closely to the magnetic size. This confirms the accuracy of the model of non-interacting superparamagnetic particles with a magnetically frustrated surface layer of about 0.5 nm thickness. For the other samples (10-nm to 21-nm), the experimental weak-field magnetization curves are modeled by more than one population of magnetically responding species. This behavior is consistent with a chemically uniform but magnetically distinct structure composed of a core and a magnetically active nanoparticle canted shell. Accordingly the weak-field signature corresponds to the total assembly of the nanoparticles. The impact of size polydispersity is also discussed.

Research paper thumbnail of Input of Microwaves for Nanocrystal Synthesis and Surface Functionalization Focus on Iron Oxide Nanoparticles

Fundamentals and Applications, 2013

ABSTRACT

Research paper thumbnail of Non-linear magnetic behavior around zero field of an assembly of superparamagnetic nanoparticles

The Analyst, 2012

The MIAplex® device is a miniaturized detector, devoted to the high sensitive detection of superp... more The MIAplex® device is a miniaturized detector, devoted to the high sensitive detection of superparamagnetic nanoprobes for multiparametric immunoassays. It measures a signal corresponding to the second derivative of the magnetization around zero field. Like any new technology, the real success of the MIAplex® detector can only be exploited through a deep understanding of the magnetic signature. In this letter, we study the magnetic behavior around zero-field of diluted lab-made and commercial ferrofluids by comparing together conventional SQUID magnetization and MIAplex® signature.

Research paper thumbnail of Size and polydispersity effect on the magnetization of densely packed magnetic nanoparticles

Journal of Applied Physics, 2012

ABSTRACT The magnetic properties of densely packed magnetic nanoparticles (MNP) assemblies are in... more ABSTRACT The magnetic properties of densely packed magnetic nanoparticles (MNP) assemblies are investigated from Monte Carlo simulations. The case of iron oxide nanoparticles is considered as a typical example of MNP. The main focus is put on particle size and size polydispersity influences on the magnetization curve. The particles are modeled as uniformly magnetized spheres isolated one from each other by a non magnetic layer representing the organic coating. A comparison with recent experimental results on gamma−\gamma-gamma−Fe$_2$O$_3$ powder samples differing by their size is given.

Research paper thumbnail of Iron oxide nanoparticles with sizes, shapes and compositions resulting in different magnetization signatures as potential labels for multiparametric detection

Acta Biomaterialia, 2013

Magnetic iron oxide nanoparticles differing in their size, shape (spherical, hexagonal, rods, cub... more Magnetic iron oxide nanoparticles differing in their size, shape (spherical, hexagonal, rods, cubes) and composition have been synthesized and modified using caffeic acid for transfer to aqueous media and stabilization of the particle suspensions at physiological pH. A super quantum interference device and the recently patented magnetic sensor MIAplex Ò , which registered a signal proportional to the second derivative of the magnetization curve, were used to study the magnetization behavior of the nanoparticles. The differences in the magnetic signatures of the nanoparticles (spheres and rods) make them promising candidates for the simultaneous detection of different types of biological molecules.

Research paper thumbnail of Size-Dependent Nonlinear Weak-Field Magnetic Behavior of Maghemite Nanoparticles

Small, 2012

The magnetic behavior at room temperature of maghemite nanoparticles of variable sizes (from 7 to... more The magnetic behavior at room temperature of maghemite nanoparticles of variable sizes (from 7 to 20 nm) is compared using a conventional super quantum interference device (SQUID) and a recently patented technology, called MIAplex. The SQUID usually measures the magnetic response versus an applied magnetic fi eld in a quasistatic mode until high fi eld values (from -4000 to 4000 kA m − 1 ) to determine the fi eld-dependence and saturation magnetization of the sample. The MIAplex is a handheld portable device that measures a signal corresponding to the second derivative of the magnetization around zero fi eld (between -15 and 15 kA m − 1 ). In this paper, the magnetic response of the size series is correlated, both in diluted and powder form, between the SQUID and MIAplex. The SQUID curves are measured at room temperature in two magnetic fi eld ranges from -4000 to 4000 kA m − 1 (-5T to 5T) and from -15 to 15 kA m − 1 . Nonlinear behavior at weak fi elds is highlighted and the magnetic curves for diluted solutions evolve from quasi-paramagnetic to superparamagnetic behavior when the size of the nanoparticles increases. For the 7-nm sample, the fi t of the magnetization with the Langevin model weighted with log-normal distribution corresponds closely to the magnetic size. This confi rms the accuracy of the model of non-interacting superparamagnetic particles with a magnetically frustrated surface layer of about 0.5 nm thickness. For the other samples (10-nm to 21-nm), the experimental weak-fi eld magnetization curves are modeled by more than one population of magnetically responding species. This behavior is consistent with a chemically uniform but magnetically distinct structure composed of a core and a magnetically active nanoparticle canted shell. Accordingly the weakfi eld signature corresponds to the total assembly of the nanoparticles. The impact of size polydispersity is also discussed.