Les matériaux nanocomposites poreux organisés présentent de nombreuses propriétés dans le domaine de l’adsorption. Cette étude est portée sur la synthèse de matériaux poreux de grande aire spécifique fonctionnalisés par des nanoparticules métalliques en visant des applications dans le domaine de l’adsorption: en phase liquide et en phase gazeuse.La première application concerne la détection en phase liquide de molécules à de faibles concentrations. Des nanocomposites composés d’une matrice poreuse de silice dans laquelle sont insérées des nanoparticules de métaux nobles (i.e. Ag@SiO2 et Au@SiO2) sont étudiés comme substrats SERS en couplant thermodynamique et spectroscopie Raman. Ce couplage de l’étude de la réponse Raman et de l’étude thermodynamique de l’adsorption a conduit à une meilleure compréhension de l’influence des particules sur le seuil de détection de la molécule. L’influence de plusieurs paramètres sur la réponse Raman de la molécule sonde et sur ses propriétés d’adsorption a aussi été étudiée (la taille des particules, la nature chimique du métal, etc.).La seconde application concerne le stockage d’hydrogène. Des nanocomposites composés de matrices poreuses de silice ou de carbone dans lesquelles sont incorporées des nanoparticules d’un métal de transition (i.e. Ni@SiO2 et Ni@Carbone) sont étudiés comme matériaux de stockage en couplant manométrie et microcalorimétrie d’adsorption. La mise en place d’une méthode de réduction adaptée a constitué une étape importante de ce travail. Ce couplage d’études thermodynamiques de l’adsorption a permis de déterminer les propriétés d’adsorption de l’hydrogène à basse température et basses pressions de ces matériaux. / Nanocomposite organized porous materials present many properties in particular in the field of adsorption. This study was based on the synthesis of porous materials of high specific surface area functionalized with metal nanoparticles focusing in particular on two applications in the field of adsorption: one in the liquid phase and the other one in the gas phase.The first application is the detection of molecules in the liquid phase at low concentrations. Nanocomposites composed of a porous silica matrix in which are inserted noble metal nanoparticles (i.e. Ag@SiO2 and Au@SiO2) are studied as SERS (Surface Enhanced Raman Scattering) substrates by coupling thermodynamics and Raman spectroscopy. The coupling of the Raman response study and the thermodynamics of adsorption study leads to a better understanding of the influence of the particles on the molecule detection threshold. The influence of various parameters on the Raman response of the probe molecule and its adsorption properties were also studied (the particle size, the chemical nature of the metal, etc.)The second application relates to the storage of hydrogen since Nanocomposites composed of porous silica or carbon matrices in which are incorporated transition metal nanoparticles (i.e. Ni@SiO2 and Ni@Carbon) were studied as storage materials by coupling the adsorption manometry and microcalorimetry. The establishment of a suitable reduction method was an important step in this work. This coupling of thermodynamic studies of the adsorption was used to determine the adsorption properties of hydrogen at low temperature and low pressures of these materials.

A síntese e caracterização de sistemas hetero-híbridos gerados a partir da 3,6-bi-2-piridil-1,2,4,5-tetrazina (bptz) e interações com ouro nanoparticulado são abordados nesta tese. O bptz foi estudado por meio de métodos espectroscópicos e teóricos, focalizando principalmente o efeito SERS associado à adsorção em nanopartículas de ouro. O mecanismo de transferência de carga para metais macroscópicos foi transposto para a condição nanoparticulada, envolvendo ligações químicas entre bptz e as nanopartículas. Os complexos estudados possuem fórmula geral [LmRu(µ-bptz)RuLm]Xn, com “L” indicando os ligantes periféricos 5-cloro-1,10-fenantrolina (Clphen) ou 4’-(fenil)-2,2&#8217:6&#8217,2&#8221-terpirdina (ptpy) e “X” os contra-íons. Foram investigadas suas espectroeletroquímicas eletrônica e SERS, e as mudanças de perfil vibracional foram modeladas, incorporando o mecanismo de transferências de carga entre complexo e o ouro, além dos mecanismos ressonantes e eletromagnéticos / The synthesis and investigation of heterohybrid systems encompassing 3,6-bi-2-pyridyl-1,2,4,5-tetrazine (bptz) and its ruthenium complexes associated with gold nanoparticles are dealt with in this thesis. Bptz was characterized by spectroscopic and theoretical techniques, focusing on its SERS spectra after the adsorption onto nanoparticles. The charge transfer mechanism in the SERS spectra of macroscopic metals was transposed to the nanoparticle condition, assuming the formation of chemical bonds between bptz and the nanoparticles. Complexes of general formula [LmRu(µ--bptz)RuLm]Xn, “L” the peripheric ligants 5-chlorine-1,10-phenantroline or 4’-(phenyl)-2,2&#8217:6&#8217,2&#8221-terpyrdine (ptpy), and “X” counter-ions were also investigated, with special emphasis on their electronic and SERS spectroelectrochemistry. The changes in the vibrational profiles were successfully explained by the occurrence of charge transfer between the adsorbed complex and gold, in addition to the electromagnetic and resonance mechanisms.

A síntese e caracterização de sistemas hetero-híbridos gerados a partir da 3,6-bi-2-piridil-1,2,4,5-tetrazina (bptz) e interações com ouro nanoparticulado são abordados nesta tese. O bptz foi estudado por meio de métodos espectroscópicos e teóricos, focalizando principalmente o efeito SERS associado à adsorção em nanopartículas de ouro. O mecanismo de transferência de carga para metais macroscópicos foi transposto para a condição nanoparticulada, envolvendo ligações químicas entre bptz e as nanopartículas. Os complexos estudados possuem fórmula geral [LmRu(µ-bptz)RuLm]Xn, com “L” indicando os ligantes periféricos 5-cloro-1,10-fenantrolina (Clphen) ou 4’-(fenil)-2,2&#8217:6&#8217,2&#8221-terpirdina (ptpy) e “X” os contra-íons. Foram investigadas suas espectroeletroquímicas eletrônica e SERS, e as mudanças de perfil vibracional foram modeladas, incorporando o mecanismo de transferências de carga entre complexo e o ouro, além dos mecanismos ressonantes e eletromagnéticos / The synthesis and investigation of heterohybrid systems encompassing 3,6-bi-2-pyridyl-1,2,4,5-tetrazine (bptz) and its ruthenium complexes associated with gold nanoparticles are dealt with in this thesis. Bptz was characterized by spectroscopic and theoretical techniques, focusing on its SERS spectra after the adsorption onto nanoparticles. The charge transfer mechanism in the SERS spectra of macroscopic metals was transposed to the nanoparticle condition, assuming the formation of chemical bonds between bptz and the nanoparticles. Complexes of general formula [LmRu(µ--bptz)RuLm]Xn, “L” the peripheric ligants 5-chlorine-1,10-phenantroline or 4’-(phenyl)-2,2&#8217:6&#8217,2&#8221-terpyrdine (ptpy), and “X” counter-ions were also investigated, with special emphasis on their electronic and SERS spectroelectrochemistry. The changes in the vibrational profiles were successfully explained by the occurrence of charge transfer between the adsorbed complex and gold, in addition to the electromagnetic and resonance mechanisms.

Des substrats SERS, élaborés selon une approche simple et à moindre coût, ont été étudiéspour la détection sans marqueurs d’ADN en vue d’applications dans le domaine du diagnostic médical.Un protocole de réduction photocatalytique assistée chimiquement conduisant à des hétérostructuresAg°/TiO2 a été optimisé. Nohttp://star.theses.fr/editeur.jsp?tefId=58411&action=save#droitsus avons montré en quoi l’utilisation d’un agent encapsulant et d’uneprocédure de nucléation-croissance permettent de contrôler la formation et l’agrégation de NPs Ag° à lasurface de couches minces TiO2. L’agrégation contrôlée des NPs conduit à des points chauds induisantune très forte amplification de l’effet SERS. Les performances des substrats SERS ont tout d’abord étévalidées par détection Raman de la molécule modèle R6G. Des études de fond, portant sur la détectionde polybases dérivées des quatre nucléobases constituant la structure de l’ADN, adénine, cytosine,guanine et thymine, ont ensuite été réalisées. Le potentiel de détection des hétérostructures Ag°/TiO2 apermis l’indexation quasi-intégrale des bandes Raman des quatre polybases étudiées, modifiées ou nonavec des groupements NH2, et nous a permis de discuter des effets d’accrochage, d’orientation etd’agencement des molécules d’ADN sur les substrats SERS. Des études complémentaires ont finalementconfirmé le potentiel de nos hétérostructures en fournissant différents aperçus sur l’hybridation despolybases et l’association de différentes polybases sur un même substrat SERS. / SERS substrates, elaborated through a simple and low-cost procedure, have been studied forthe label-free detection of DNA in the view of applications in the medical diagnostic field. A chemicallyassisted photocatalytic reduction protocol leading to an Ag°/TiO2 heterostructure has been optimized.We have shown how the use of an encapsulating agent and a nucleation-growth procedure enable tocontrol the formation and aggregation of Ag° NPs at the surface of TiO2 thin films. The controlledaggregation of NPs leads to hot points inducing a very strong amplification of the SERS effect.Performances of the SERS substrate have first been evaluated through the Raman detection of the R6Gmodel molecule. Thorough studies dealing with the detection of polybases derived from the fournucleobases constituting the DNA structure, adenine, cytosine, guanine, and thymine, have then beenconducted. The detection potential of the Ag°/TiO2 heterostructure enabled a nearly exhaustiveindexation of the Raman bands for the four studied polybases, modified or not with NH2 groups, and todiscuss on binding, orientation, and ordering effects of the DNA molecules on the SERS substrate.Complementary studies finally enabled us to confirm the potential of our heterostructure by providingdifferent insights on the polybase hybridization and the association of different polybases on a sameSERS substrate.

Des substrats SERS, élaborés selon une approche simple et à moindre coût, ont été étudiéspour la détection sans marqueurs d’ADN en vue d’applications dans le domaine du diagnostic médical.Un protocole de réduction photocatalytique assistée chimiquement conduisant à des hétérostructuresAg°/TiO2 a été optimisé. Nohttp://star.theses.fr/editeur.jsp?tefId=58411&action=save#droitsus avons montré en quoi l’utilisation d’un agent encapsulant et d’uneprocédure de nucléation-croissance permettent de contrôler la formation et l’agrégation de NPs Ag° à lasurface de couches minces TiO2. L’agrégation contrôlée des NPs conduit à des points chauds induisantune très forte amplification de l’effet SERS. Les performances des substrats SERS ont tout d’abord étévalidées par détection Raman de la molécule modèle R6G. Des études de fond, portant sur la détectionde polybases dérivées des quatre nucléobases constituant la structure de l’ADN, adénine, cytosine,guanine et thymine, ont ensuite été réalisées. Le potentiel de détection des hétérostructures Ag°/TiO2 apermis l’indexation quasi-intégrale des bandes Raman des quatre polybases étudiées, modifiées ou nonavec des groupements NH2, et nous a permis de discuter des effets d’accrochage, d’orientation etd’agencement des molécules d’ADN sur les substrats SERS. Des études complémentaires ont finalementconfirmé le potentiel de nos hétérostructures en fournissant différents aperçus sur l’hybridation despolybases et l’association de différentes polybases sur un même substrat SERS. / SERS substrates, elaborated through a simple and low-cost procedure, have been studied forthe label-free detection of DNA in the view of applications in the medical diagnostic field. A chemicallyassisted photocatalytic reduction protocol leading to an Ag°/TiO2 heterostructure has been optimized.We have shown how the use of an encapsulating agent and a nucleation-growth procedure enable tocontrol the formation and aggregation of Ag° NPs at the surface of TiO2 thin films. The controlledaggregation of NPs leads to hot points inducing a very strong amplification of the SERS effect.Performances of the SERS substrate have first been evaluated through the Raman detection of the R6Gmodel molecule. Thorough studies dealing with the detection of polybases derived from the fournucleobases constituting the DNA structure, adenine, cytosine, guanine, and thymine, have then beenconducted. The detection potential of the Ag°/TiO2 heterostructure enabled a nearly exhaustiveindexation of the Raman bands for the four studied polybases, modified or not with NH2 groups, and todiscuss on binding, orientation, and ordering effects of the DNA molecules on the SERS substrate.Complementary studies finally enabled us to confirm the potential of our heterostructure by providingdifferent insights on the polybase hybridization and the association of different polybases on a sameSERS substrate.