Developing new materials with desired properties is a vital component of emerging technologies. Functional hybrid compounds make an important class of advanced materials that let us synergistically utilize the key features of the organic and inorganic counterparts in a single composite, providing a very strong tool to develop new materials with ”engineered” properties. The research presented here, summarizes efforts in the development of facile and efficient methods for the fabrication of three- and two-dimensional inorganic-organic hybrids based on layered oxide perovskites. Microwave radiation was exploited to rapidly fabricate and modify new and known materials. Despite the extensive utilization of microwaves in organic syntheses as well as the fabrication of the inorganic solids, the work herein was among the first reported that used microwaves in topochemical modification of the layered oxide perovskites. Our group specifically was the first to perform rapid microwave-assisted reactions in all of the modification steps including proton exchange, grafting, intercalation, and exfoliation, which decreased the duration of multi-step modification procedures from weeks to only a few hours. Microwave-assisted grafting and intercalation reactions with n-alkyl alcohols and n-alkylamines, respectively, were successfully applied on double-layered Dion-Jacobson and Ruddlesden-Popper phases (HLaNb2O7, HPrNb2O7, and H2CaTa2O7), and with somewhat more limited reactivity, applied to triple-layered perovskites (HCa2Nb3O10 and H2La2Ti3O10). Performing neutron diffraction on n-propoxy-LaNb2O7, structure refinement of a layered hybrid oxide perovskite was then tried for the first time. Furthermore, two-dimensional hybrid oxides were efficiently prepared from HLnNb2O7 (Ln = La, Pr), HCa2Nb3O10, HCa2Nb2FeO9, and HLaCaNb2MnO10, employing facile microwave-assisted exfoliation and post-exfoliation surface-modification reactions for the first time. A variety of surface groups, saturated or unsaturated linear and cyclic organics, were successfully anchored onto these oxide nanosheets. Properties of various functionalized metal-oxide nanosheets, as well as the polymerization of some monomer-grafted nanosheets, were then investigated for the two-dimensional hybrid systems.

Les poly(3-hydroxyalcanoate)s ou PHAs sont des biopolyesters linéaires biodégradables et biocompatibles synthétisés par des microorganismes bactériens en tant que réserve de carbone et d'énergie. Ils sont synthétisés par des bactéries à partir de ressources renouvelables et la diversité de leurs structures possibles se traduit par un large éventail de polymères ayant des propriétés mécaniques très différentes. Nous avons tout d'abord testé les capacités de production de PHAs de nouvelles souches bactériennes marines provenant de tapis microbiens de Polynésie française, en utilisant, entre autres, des substrats naturels comme l'huile de coprah, le glucose et l'acide oléique. Nous avons notamment montré que la souche Pseudomonas guezennei est capable de produire des PHAs avec des taux d'insaturation contrôlés et de masse molaire très élevée. Puis, des oligomères de PHAs fonctionnalisés de structures contrôlées portant des fonctions terminales alcynes ou alcènes ont été préparés par transestérification. Ces oligomères ont ensuite été utilisés pour l'élaboration par chimie click de copolymères amphiphiles greffés EPS-g-PHA avec des exopolysaccharides (EPS) bactériens. Enfin la dernière partie de ces travaux a consisté en la réalisation d'un support de croissance pour le développement de cellules souches pour l'ingénierie tissulaire combinant les propriétés mécaniques des PHAs et les propriétés hydrophiles et bioactives des EPS / Poly(3-hydroxyalkanoate)s, or PHAs, are linear biodegradable and biocompatible biopolyesters synthesized by bacterial microorganisms as energy and carbon supply. They are synthesized by bacteria from renewable resources and the diversity of the achievable structures leads to a large range of mechanical properties. First, we studied the PHAs production ability of several new marine bacteria strains, isolated from microbial mats from French Polynesia, using, among others, natural substrates such as coprah oil, glucose and oleic acid. We showed particularly that the strain Pseudomonas guezennei was able to produce PHAs with controlled amounts of insaturations and high molar masses. Then, we prepared functionalized PHAs oligomers with controlled structure and bearing a terminal alkyne or alkene function. Following that, these oligomers were used to elaborate amphiphilic by click chemistry graft copolymers EPS-g-PHA with bacterial exopolysaccharide (EPS). Finally, the last part of this work was the making of a scaffold for stem cell culture for tissue engineering which combined the mechanical properties of PHAs and the hydrophilicity and bioactive properties of EPS

Doctor of Philosophy / Department of Chemistry / Duy H. Hua / Carbon nanotubes are allotropes of carbon comprising of one or more grapheme sheets seamlessly joined together to form a cylinder. They are classified as single-walled carbon nanotubes (SWNTs) or multi-walled carbon nanotubes (MWNTs). They have potential applications ranging from conductive and high reinforcement material components, nano interconnection in electronic devices to drug delivery in biological systems. Current methods of production are high temperature arc-discharge, laser ablation of graphitic materials and chemical vapor deposition. These methods give tubes that are impure and highly heterogeneous in length, diameter and chirality thus leading to mixture metallic and semiconducting tubes. Effective application of such carbon nanotubes requires cumbersome, harsh and expensive purification and sorting into like forms. Such treatments usually compromised the structural integrity of the tubes and hence their mechanical and electrical properties. Also pristine carbon nanotubes are insoluble in most solvents. Solubility in basic organic solvents is crucial prior to their application, which requires some level of chemical manipulation or functionalization on the tubes. Currently methods of functionalization are unpredictable and limited to few oxidation reactions. A novel rational synthetic chemical approach to [12, 12] arm-chair carbon nano tube with pre-defined diameter and length has been explored utilizing cheap and simple organic building blocks and results achieved so far have been presented in this dissertation. Two approaches were employed to form the carbon-rich beltene (32) before its final conversion to the target single-walled carbon nanotube (SWNT) 1. A survey on carbon nanotubes and their related structures including their potential applications and properties are presented in chapter 1. In the second chapter an iron template-assisted olefin metathesis via a ferrocene intermediate served as an anchor for an effective cyclization. In chapter 3, an un-assisted olefin metathesis pathway was explored. Both approaches use a series of benzyl halide carbonylation coupling and Diels-Alder reactions to synthesize some of the key intermediates. The protocol presented in this dissertation may be used to produce functionalized carbon nanotubes with predefined length and diameter tailored for specific applications to be produced in kilogram scale for the first time since its discovery in 1991. Such an approach is expected to address most if not all of the problems associated with the traditional methods of producing carbon nanotubes.

Différents travaux de recherche ont été décrits dans cette thèse. Les travaux de recherche peuvent être résumés comme suit. Le premier chapitre a porté sur l'identification d’inhibiteurs puissants efficaces vis-à-vis de de l'isoenzyme anhydrase carbonique humaine I (hCAI). Considérant l'importance pharmacologique de trouver des inhibiteurs (CAIs) et des activateurs (AACs) sélectifs aux isoformes de l’anhydrase carbonique ), l'anhydrase carbonique humaine I (hCAI) a été confrontée en parallèle à diverses bibliothèques dynamiques constitutionnelles (CDL). Dans le deuxième chapitre, des réseaux constitutionnels dynamiques ont été préparés sous forme de systèmes membranaires liquides et solides agissant comme un réseau pour le transport spécifique des ions lanthanides. Le transport est basé sur la capacité de complexation des lanthanides (La + 3, Lu + 3, Eu + 3) avec les groupes polyéther fonctionnels situés dans les matériaux membranaires. Dans le troisième chapitre, l'approche proposée consiste en l'utilisation de membranes liquides ioniques supportées (SILMs) comprenant deux enzymes différentes de l'anhydrase carbonique, l’enzyme thermo-résistante SspCA et l'enzyme bovine-CA, qui catalysent la réaction de conversion réversible du CO2 en bicarbonate en favorisant la force motrice vers le transport de CO2. La stabilité des membrane, leur perméabilité vis-à-vis de CO2 et de N2 ainsi que la sélectivité idéale (CO2 / N2) ont été déterminées pour les membranes développées. Le quatrième chapitre porte sur la synthèse et la caractérisation de membranes polymères denses pour une application en séparation de gaz. Les mesures de perméabilité aux gaz des membranes polymères synthétisées ont montré que la perméabilité de CO2 est supérieure à celle des autres gaz testés (CH4 et N2). Dans le dernier chapitre, des membranes de PVDF ont été fonctionnalisées avec une enzyme, la phosphotriestérase (PTE), selon deux méthodes différentes pour construire un réacteur à membrane biocatalytique (BMR) avec pour finalité la bioconversion et la séparation sélective du substrat paraoxon. La première méthode met en œuvre une dispersion réversible de nanoparticules magnétiques de PTE qui est immobilisée à la surface de la membrane de PVDF sous l’effet d'un champ magnétique externe. A l’inverse, la seconde méthode porte sur le greffage chimique de l'enzyme PTE, après modification de la surface de la membrane de PVDF native (DAMP-GA-enzymatique). Les deux techniques d'immobilisation d'enzymes ont montré une bonne efficacité et une sensibilité à l'égard de la bioconversion du paraoxon dans les différentes conditions appliquées dans un réacteur à membrane biocatalytique (BMR).De façon globale, les concepts développés dans ce travail de thèse permettront d’ouvrir de nouvelles pistes de recherche allant vers le développement d'une membrane polymère sélective au transport d’ions, de gaz mais aussi active dans les réactions catalytiques enzymatiques grâce à un contrôle bio-moléculaire au niveau des matériaux membranaires. / Different research works have been described in this thesis. The research works can be summarized as the following. The first chapter deals with the identification of effective potent inhibitors for the human carbonic anhydrase I (hCAI) isozyme. Considering the pharmacological importance to find selective CA inhibitors (CAIs) and CA activators (CAAs), human carbonic anhydrase I (hCAI) has been subjected to a parallel screening of various constitutional dynamic libraries (CDL). In the second chapter, constitutional dynamic networks have been used in liquid and solid membrane systems as a carrier network for transporting lanthanides. The transport is based on the complexing ability of lanthanides metals (La+3, Lu+3, and Eu+3) with the functional polyether groups in the membrane materials. In the third chapter, the proposed approach consists in using supported ionic liquid membranes (SILMs) comprising two different carbonic anhydrase enzymes, the thermo-resistant SspCA enzyme and the Bovine-CA enzyme, which catalyze the reaction of reversible conversion of CO2 to bicarbonate, enhancing the driving force for CO2 transport. Membrane stability, CO2 and N2 permeability and (CO2/N2) ideal selectivity were determined for the membranes developed. In the fourth chapter, the research work consists in the synthesis and characterization of dense polymeric membranes for gas separation application. The gas permeability measurements for the synthesized polymeric membranes showed that the permeability of CO2 is higher than other used gases (N2 and CH4). In the last chapter, two different methods of PVDF membrane functionalization with a phosphotriesterase (PTE) enzyme have been developed to construct biocatalytic membrane reactor (BMR) for bioconversion and selective separation of paraoxon substrate. The first method employs reversible dispersion of magnetic nanoparticle immobilized with PTE using an external magnetic field on the surface of native PVDF membrane. On the contrary, the second method comprises chemical grafting of the PTE enzyme, after surface modification of the native PVDF membrane (DAMP-GA-Enzyme). Both methods of enzyme immobilization showed good efficiency and sensitivity towards the bioconversion of paraoxon substrate at different conditions applied in a biocatalytic membrane reactor (BMR).In general, the concepts developed in this thesis research work will help bring new tracks on the way to the development of a polymeric membrane for selective ion and gas separation but also for selective catalytic reaction under bio(molecular) control.

<p></p><p></p><p>The unprecedented properties of 2D materials such as graphene and MoS2 have been researched extensively [1,2] for a range of applications including nanoscale electronic and optoelectronic devices [3–6]. Their unique physical and electronic properties promise them as the next generation materials for electrodes and other functional units in nanostructured devices. However, successful incorporation of 2D materials into devices entails development of high resolution patterning techniques that are applicable to 2D materials. Patterning at the sub-10 nm scale is particularly of great interest as the next technology nodes require patterning of (semi)conductors and insulators at 7 nm and 5 nm scales for nanoelectronics. It will also benefit organic photovoltaic cells as phase segregation of p/n-type semiconducting polymers on 2D electrodes at length scales smaller than the typical exciton diffusion length (10 nm)</p> <p>is expected to improve the charge separation efficiency [7].</p><br><p></p><p></p><p>Characterizing locally modulated properties of non-ovalently functionalized 2D materials requires high-resolution imaging techniques capable of extracting measurements of various physical/chemical properties. One such method is scanning probe microscopy (SPM) [18–21]. In Chapter 1, we present a brief review of SPM modalities, some of which are used to characterize interfacial properties, such as conductivity and local contact potential differences that can be modulated by amphiphilic assemblies [17, 22]. Atomic force microscopy (AFM) is one of main techniques that we use to determine topography. All imaging in this work were performed in attractive AC mode [23,24] in order to minimize disruption to the self-assembly of the amphiphiles by the scanning tip.</p><br><p></p><p></p><p>One challenge of using SAMs for locally modulated functionalization is that the proximity to the nonpolar interface can modify the behavior of the functionalities present on the surface in conjunction with the steric hindrance of 2D molecular assemblies. For instance, ionizable functional groups, one of the strongest local modulators of surface chemistry, undergo substantial pKa shifts (in some cases, > 5 units) at nonpolar interfaces, limiting their ability to ionize. In order to apply molecular assembly to create 2D chemical patterns, we needed to design alternative structures that can avoid such penalties against the intrinsic properties of functionalities present in the assemblies. Among amphiphiles, we observed that the chiral centers of phospholipids have the potential of elevating the terminal functional group in the head from the surface for improved accessibility. We refer to this type of assembly as a ’sitting’ phase. Chapter 2 describes sitting phase assembly of phospholipids; the projection of the terminal functionality allows it to maintain solution phase-like behavior while the dual alkyl tails provide additional stabilizing interactions with the substrates. Given the diversity of phospholipid architecture [25], the sitting phase assembly suggests the possibility of greatly diversifying the orthogonality of the chemical patterns, allowing highly precise control over surface functionalities.</p><br><p></p><p></p><p>While a variety of methods including drop-casting [26–28] and microcontact printing [29] have been used previously by others for noncovalent assembly of materials on the surface, they mostly address patterning scale in the sub-μm range. Here, we utilize Langmuir-Schaefer(LS) transfer, which has been historically used to transfer standing phase multilayers [30], and lying-down domains of PCDA at < 100 nm scales in the interest of molecular electronics [14, 31–33], as our sample preparation technique. LS transfer is remarkable in that the transferred molecules relinquish their pre-existing interactions in the standing phase at air-water interface to undergo ∼ 90◦ rotation and assemble into the striped phase on a substrate. This introduces the possibility of modulating local transfer rate across the substrate by manipulating local environment of the molecules. Thus, LS transfer has the potential to offer spatial control over the noncovalent chemical functionalization of the 2D substrate, essential in device applications.</p><br><p></p><p></p><p>In Chapter 3 and 4, We make comparative studies of various experimental factors such as surface pressure, temperature and molecular interactions that affect the efficiency of LS conversion. Considering the energetics of the transfer process, we predicted that the rate of transfer from the air-water interface to the substrate should be the highest from the regions around defects, which would be the energetically</p> <p>least stable regions of the Langmuir film [34, 35]. In Langmuir films, two phases of lipid assemblies—liquid expanded (LE) and liquid condensed (LC)—often coexist at the low surface pressures (< 10 mN/m) used for sample preparation. Hence, we hypothesized that the microscale structural heterogeneity of Langmuir films could be translated into microscale patterns in the transferred film on HOPG. We compare the transfer rates between LE and LC phases and investigate the impacts of physical conditions during LS transfer such as temperature, packing density, dipping rate and contact time to conclude that local destabilization of Langmuir films leads to increased transfer efficiency. (Chapter 3)</p><p><br></p><p></p><p>As in the case of lipid membranes that reorganize routinely based on the structure of the constituent molecules [36–38], the structure of Langmuir films is strongly dependent on the molecular structures of the constituent molecules [39–43]. Accordingly, we expected the molecular structures/interactions to provide additional control over the LS transfer process. In Chapter 4, we compare domain morphologies and the average coverages between three single chain amphiphiles and two phospholipids, each</p><p></p><p> </p><p>of which contain hydrogen bonding motifs of varying strengths. We show that by influencing the adsorption and diffusion rates, molecular architecture indeed influences LS conversion efficiency and subsequent assembly on the substrate. The presence of strong lateral interactions limits transfer and diffusion, forming vacancies in the transferred films with smaller domain sizes while weaker intermolecular interactions enabled high transfer efficiencies.</p><p></p><p><br></p><p></p>

Les polyazacycloalcanes sont largement utilisés pour l’élaboration de radiopharmaceutiques destinés à la médecine nucléaire. Ces structures, et plus particulièrement celles dérivées du cyclam, permettent une complexation idéale du cuivre et ainsi une application en imagerie TEP, avec l’utilisation du 64Cu, ou en radiothérapie grâce à l’isotope 67Cu. Le cyclam doit, en plus d’être N-fonctionnalisé par des bras coordinants, disposer d’une fonction supplémentaire permettant la bioconjugaison à une biomolécule pour un ciblage spécifique des cellules cancéreuses. Une première partie de cette thèse a porté sur la synthèse du cyclam monopicolinate C-fonctionnalisé par une fonction de bioconjugaison de type benzyle isothiocyanate. Cette synthèse, basée sur des travaux antérieurs du laboratoire, a nécessité la mise au point d’une méthode d’alkylation régiospécifique du cyclam C-fonctionnalisé par le biais de protections sélectives des atomes d’azote du macrocycle. Le ligand a ensuite été étudié in vitro et in vivo, par nos collaborateurs nantais du CRCINA, pour l’imagerie immuno-TEP du myélome multiple.La seconde partie de ce travail s’est consacrée à l’élaboration d’un dérivé polyfonctionnel du cyclam possédant deux fonctions permettant le ciblage des cellules tumorales. Ce composé a été synthétisé au sein du laboratoire brestois puis étudié, in vitro et in vivo, dans les locaux de la NECSA en Afrique duSud pour l’imagerie TEP du cancer du sein.Ces deux projets ont permis d’obtenir une preuve de concept en imagerie TEP ce qui confirme le potentieldes ligands dérivés de cyclam C-fonctionnalisés pour l’élaboration de radiopharmaceutiques à base de cuivre pour la médecine nucléaire. / Polyazacycloalkanes are wildly used in the conception of radiopharmaceuticals for nuclear medicine. These structures, and especially cyclam derivatives, provide ideal complexation properties of copper, which can be applied in nuclear medicine applications with the 64Cu isotope for PET imaging or with 67Cu for radiotherapy purpose. Cyclams derivatives have to be N-functionalized with coordinative arms, and moreover include an additional function especially introduced for the bioconjugation of a biomolecule in the aim to preferentially target cancer cells.The first project treated in this manuscript consisted of the synthesis of a monopicolinate cyclam C-functionalized with a benzyl isothiocyanate function for the bioconjugation. Based on precedent results obtained in the Lab, a regiospecific alkylation method has been developed for the synthesis of this ligand.This method implies the selective protection and deprotection of the macrocycle nitrogen atoms. This ligand, once obtained, has been studied in vitro and in vivo, by our collaborators of the CRCINA in Nantes, for multiple myeloma immuno-PET imaging.The second project of this work is dedicated to the conception of a radiopharmaceutical based on apolyfunctionnal cyclam which bear two different moieties allowing the targeting of cancer cells. This ligand has been synthesized in our Lab in Brest and studied, in vitro and in vivo, in the South African NECSA company for breast cancer PET imaging.These two projects were elaborated in the aim to obtain a proof of principle in PET imaging and to confirm the high potential of C-funcitonnalized cyclam derivatives for nuclear medicine applications.

The thesis constitutes investigations from two distinct areas of research. One part deals with controlling and modulating the conformation of linear polymer in solution. Folding of a polymer chain has been achieved by utilising weak non-covalent interactions interaction like metal ion binding, charge-transfer complex formation and solvophobic effect in tandem. The second part of the thesis deals with synthesis and characterization of end-functionalized polymers prepared by melt-transesterification. The thesis is divided into five chapters. Chapter 1 provides a general introduction on foldamers – a class of polymers that adopts an ordered conformation in solution and various approaches to obtain end-functionalized polymers. Chapter 2 describe the attempts to improve the association constant (based on earlier works reported by Ghosh and Ramakrishnan) between the external folding agent and the polymer repeat unit. The polymer used in this study constitutes an electron deficient pyromellitic dimide units (PDI) linked with a flexible oxyethylene glycol spacer. An electron rich dialkoxy naphthalene (DAN) serves as the folding agent which forms a charge-transfer (C-T) complexation with the electron deficient aromatic units (PDI) in the polymer backbone and effects the folding. The folding agent has the metal ion as its integral part and this aids the interaction between electron-deficient and electron-rich aromatic units by complexing with oxyethylene glycol spacer. Thus folding is due to the synergistic effect of C-T complex formation and metal ion binding. Further a new polymer with larger -surface area of electron acceptor units was prepared with naphthalene dimide (NDI) unit instead of PDI unit which is expected to show higher folding propensity. Chapter 3 explores the possibility of modulating the folding of the donor acceptor (D-A) polymer. A D-A polymer consist of adjacently placed DAN and PDI units linked by an oxyethylene glycol spacer. Folding of the D-A polymer is effected in the presence of suitable metal ion that binds to the oxyethyleneglycol spacer. Random copolymers with segments of alternately placed D-A pairs and segments that is devoid of D-A pairs were prepared. Depending on composition of the random copolymer, the stack length was shown to be modulated as evident from UV-visible and NMR titration experiments. Following a similar approach, a two step folding of the synthetic polymer was demonstrated. The synthesis and characterization of end functionalized polyesters by melt transesterification is discussed in chapter 4. Well defined linear polymer with propargyl group as the end functionalizable group is prepared by the polycondensation of AB type monomer whereas polycondensation of AB2 type monomer leads to peripherally functionalized hyperbranched polymer. Azide-alkyne ‘click’ reactions carried out at the chain end of linear polyester with fluorophores allowed the estimation of the molecular weight by UV-visible and fluorescence spectroscopic method which is compared with estimation from 1H-NMR. Similarly the glass-transistion temperature of hyperbranched polyester is modulated by the peripheral functionalization with various organic azides by ‘click’ reaction. Chapter 5 gives the conclusion and future directions based on the findings from the thesis work.

This thesis begins with a brief overview of supramolecular chemistry and selfassembly and simple examples derived from Nature that provide the motivation for the work presented here. The concept of a synthetic noncovalent toolbox is then introduced. The discussion then focuses more explicitly on side-chain and main-chain functionalized motifs and the methodologies employed in supramolecular polymer functionalization. The primary hypothesis of the thesis is that the combination of supramolecular strategies, ring-opening metathesis polymerization, and a well-understood toolbox of functionalities capable of noncovalent interactions, comprises a method for generating bioinspired materials. This hypothesis was tested by synthesizing unique functionalized supramolecular polymers that allowed for a detailed understanding of the orthogonality of noncovalent interactions and how such interactions can begin to mimic the complexity of functional biomaterials. The strategies and methods discussed in the synthesis of these bioinspired materials are divided into three chapters: (1) an exploration of the self-sorting phenomena between two non-complementary pairs of hydrogen bonds along polymer side-chains, (2) the extension of the self-sorting concept to include a metal coordination moiety, and (3) the side-chain functionalization strategies of chapters 2 and 3 in combination with the main-chain ROMP methodologies discussed in chapter 1 to form orthogonally self-assembled multifunctional block copolymers. The main results of this thesis include the results that multifunctional block copolymers can be fashioned via ROMP, functionalized in both the main- and side-chains, and self-assembled in an orthogonal fashion. In addition, these studies have found that self-sorting between pairs of non-complementary hydrogen bonding motifs can occur in supramolecular synthetic systems, that the interactions are extremely solvent dependent and that these interactions can result in unexpected phenomena. These results demonstrate the importance of a fully understood toolbox for the rapid development of supramolecular materials. The knowledge derived from this toolbox and presented in chapters 2, 3, and 4, allows for the careful selection of compounds for cleverly designed self-assembly materials inspired by Nature. Finally, conclusions are drawn to the success of the synthetic toolbox and the various strategies presented herein, and potential future directions are discussed.

Ce travail de thèse est axé sur l'élaboration de techniques de bioremédiation des sols contaminés par les Polluants Organiques Persistants (POP) en particulier sur deux familles de polluants : les Hydrocarbures Aromatiques Polycyliques et les dioxines (PCDD/F). La dégradation des POP présente deux obstacles majeurs à l'efficacité des traitements biologiques par voie fongique : la faible biodisponibilité des POP et la difficulté d'amorcer l'oxydation de molécules aussi stables chimiquement. Afin de lever ces verrous technologiques, nous proposons de coupler une oxydation chimique douce à l'oxydation biologique par les champignons telluriques saprotrophes et d'utiliser l'amidon pour améliorer la proximité spatiale entre le polluant et les réactifs d'oxydation. La première partie de ce travail de thèse consiste à fonctionnaliser de l'amidon de pomme de terre par la 1,4-butane sultone et l'anhydride 2-octén-1-ylsuccinique selon différentes conditions de synthèses. En comparaison avec l'amidon natif, un des produits obtenus, P9*, possède des propriétés surfactantes très intéressantes pour notre étude. En effet, P9* augmente la solubilité aqueuse de l'amidon par un facteur de 35 (22,60 g.L⁻¹) et stimulent 33 fois la solubilisation aqueuse du benzo[a]pyrène (BaP). Pour la seconde partie, l'utilisation d'un système d'étude simplifié où le champignon est cultivé en milieu minéral en conditions axéniques nous a permis de déterminer les paramètres (souche fongique, type et dose d'oxydant chimique) optimaux pour l'élaboration d'une méthode de dégradation des POP au laboratoire. Des études comparatives de dégradation du BaP sont donc réalisées in vitro par différents processus d'oxydation chimique (réaction de Fenton) et/ou biologique. Le couplage des deux procédés conduit à une dégradation du PaP de 40,0%. De plus, l'encapsulation du BaP par les nanosphères d'amidon P9* permet une dégradation du polluant de 64,6% par le réactif de Fenton. Deux souches fongiques (Penicillium brasilianum et Fusarium solani) sont ensuite utilisées pour des essais de dégradation conduits au laboratoire en microcosmes de sols historiquement contaminés par les PCDD/F. L'inoculation de la souche endogène P. brasilianum en présence de copeaux de carton comme agent structurant a conduit à une diminution de la toxicité des PCDD/F de 40,5% après seulement 2 mois d'incubation par rapport au sol témoin. Ce travail de thèse ouvre ainsi de nouvelles perspectives de techniques de remédiation des sols pollués par les POP à faible coût économique et respectueuses de l'environnement. / This thesis work deals with the development of bioremediation techniques for contaminated soils by Persistent Organic Pollutants (POPs) such as : Polycyclic Aromatic Hydrocarbons and dioxins (PCDD/F). The degradation of POPs has two main obstacles to efficient biological treatments by fungi : the low bioavailability of POPs and the difficulty of initiating the oxydation of molecules as stable as others. To overcome these technological barriers, we propose to couple a mild chemical oxidation to biological oxidation by saprotrophic telluric fungi and to use starch to improve the spatial proximity between the pollutant and oxidizing reagents. The first part of this study is to functionalize native potato starch by 1,4-butane sultone and 2-octenyl-1-succinic anhydride according to different synthesis conditions. In comparison with native starch, one of the processed products, P9*, has very interesting surfactant properties for our study. Indeed, P9* increases starch apparent aqueous solubility by a factor of 65 (22.60 g.L⁻¹) and stimulates 33-fold benzo[a]pyrene (BaP) aqueous solubilization. For the second part, the use of a simplified study system where the fungus is cultivated in mineral medium under axenic conditions allowed us to determine the best parameters (fungal strainsn type and dose of chemical oxydant) for the development of a POPs degradation method in the laboratory. Comparative studies of BaP degradation are therefore carried out in vitro by different processes of chemical (Fenton's reagent) and/or biologial oxidation. The coupling of the two processes leads to a BaP degradation of 40.0%. Moreover, the BaP encapsulation by starch nanospheres P9* allows a pollutant degradation of 94.6% by the Fenton reagent. Two fungal strains (Penicillium brasilianum and Funsarium solani) are then used for the degradation lab experiment in historically PCDD/F contaminated soil microcosms. the inoculation of the endogene strain P.brasilianum in presence of cardboard chips as a bulking agent led to a decrease in PCDD/F toxicity of 40.5% after only two months of incubation compared to the controm soil. This PhD work draws new perspectives for remediation techniques of contaminated soils by POPs that are cost-effective and environmentally friendly.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-09-20T12:53:17Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO- VERSÃO FINAL -Biblioteca.pdf: 3304564 bytes, checksum: be295edea976cdf452e4a26cacd96e9e (MD5) / Made available in DSpace on 2016-09-20T12:53:17Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) DISSERTAÇÃO- VERSÃO FINAL -Biblioteca.pdf: 3304564 bytes, checksum: be295edea976cdf452e4a26cacd96e9e (MD5) Previous issue date: 2016-02-29 / FACEPE / Com o avanço da nanotecnologia, o uso de nanopartículas (NPs) metálicas, e semicondutoras, no desenvolvimento de biossensores vem aumentando nos últimos anos. Sua utilização vem proporcionando um aumento da área superficial, promovendo uma imobilização mais efetiva de biomoléculas, e espécies eletroativas, a fim de melhorar a sensibilidade de detecção do biossensor. Dentre essas NPs, estão os pontos quânticos (PQs), nanocristais com propriedades ópticas e semicondutoras únicas, as quais podem ser moduladas por seu tamanho. Os PQs podem ser utilizados em plataformas para biossensores eletroquímicos através de sua imobilização como intermediários entre o bioreceptor e a superfície do eletrodo. Nesse contexto, esse trabalho objetivou empregar e avaliar a utilização de PQs de CdTe carboxilados em uma plataforma biossensora eletroquímica baseada em eletrodo de carbono vítreo modificado com polipirrol aminado. Posteriormente, o anticorpo IgG (Imunoglobulina G Humana) foi imobilizado e a plataforma foi aplicada na detecção do anti-IgG. A imobilização dos PQs e do IgG foi avaliada de forma covalente e por adsorção. No primeiro caso, o eletrodo modificado pelo pirrol aminado foi imerso por 24 horas em uma solução contendo 2 mmol L-1 de EDC e 5 mmol L-1 de Sulfo-NHS para a formação de ligações amidas entre os PQs e a superfície modificada. Antes da imobilização do IgG, foram realizados estudos de conjugação em meio homogêneo a partir do ensaio fluorescente em microplaca (EFM). Esse estudo foi realizado a fim de correlacionar a conjugação nos meios homogêneo/heterogêneo e desenvolver um método com fins de aprimorar com maior rapidez a imobilização de biomoléculas na plataforma biossensora. Dessa forma, após o EFM, a superfície modificada por PQs foi avaliada frente a diferentes quantidades de IgG, EDC e Sulfo-NHS, adquiridas através da melhor e pior condição da EFM. A partir do resultado do EFM, foi adotada como melhor condição a do sistema com a maior quantidade de EDC e Sulfo-NHS e menor concentração de IgG, o qual apresentou um aumento relativo da fluorescência de 960%, enquanto que a pior condição foi obtida a partir da menor quantidade de agentes de acoplamento e de IgG, com aumento relativo da fluorescência de 80%. Todas as etapas de modificações do eletrodo foram monitoradas por voltametria cíclica (VC) e espectroscopia de impedância eletroquímica (EIE). Para o eletrodo de carbono vítreo modificado com polipirrol aminado, as análises eletroquímicas não apresentaram grandes variações em relação ao eletrodo limpo. Já com a imobilização dos PQs de CdTe carboxilados, os resultados indicaram uma redução no processo de transferência de carga, evidenciado através da diminuição e do deslocamento da corrente de pico na região de oxidação da voltametria cíclica, e do aumento do semicírculo apresentado nos dados da impedância eletroquímica. Posteriormente, a voltametria cíclica na presença do anticorpo IgG apresentou também uma diminuição e um deslocamento gradual das correntes de pico catódicas e anódicas, indicando a imobilização dessa biomolécula na superfície do eletrodo. As análises de EIE foram coerentes com as da VC. Foi observada correlação entre as avaliações no eletrodo e na EFM, indicando que a melhor condição no EFM será uma escolha efetiva para a plataforma. Os resultados também indicaram que os PQs e IgGs foram imobilizados preferencialmente de forma covalente. As avaliações preliminares também indicaram que a interface modificada por pirrol aminado e PQs carboxilados foi capaz de detectar anti-IgGs na faixa de ng mL-1, revelando-se como um potencial para ser utilizada na detecção de biomarcadores de diagnóstico. / The use of metallic, and semiconductor, nanoparticles (NPs) for developing biosensors has been expanding in recent years. NPs can provide an increase of the biosensors’ surface area, by promoting a more effective immobilization of biomolecules, as well as electroactive species, in order to improve the sensitivity of these devices. Among these NPs, there are the quantum dots (QDs), nanocrystals with unique optical and semiconductor properties that can be applied in electrochemical biosensors platforms as intermediaries between bioreceptors and the electrode surface. Thus, in this context, this study aimed to evaluate and employ carboxyl-coated CdTe PQs in an electrochemical platform based on a vitreous carbon electrode modified by amino functionalized polypyrrole. Subsequently, the IgG (human immunoglobulin G) antibody was immobilized on the platform that was tested by detecting anti-IgG biomolecules. The QDs, as well as the IgG, immobilization was evaluated by covalent coupling and by adsorption. In the first case, the electrode modified by polypyrrole was immersed, for 24 hours, in a solution containing 2 mmol L-1 of EDC and 5 mmol L-1 of Sulfo-NHS to promote amide bonds between the modified surface and QDs. Before IgG immobilization, conjugation experiments were also performed in homogeneous medium by using the fluorescent microplate assay (FMA). This study was conducted to correlate the conjugations in homogeneous/heterogeneous media in order to develop a method for improving more quickly the biomolecules’ immobilization on the biosensor platform. Thus, after the EFM, the electrode modified by QDs was evaluated by using different amounts of IgG, EDC and Sulfo-NHS, acquired from the best and the worst condition of FMA. From the result of the FMA, it was adopted as the best system that one composed by the greatest amount of EDC and Sulfo-NHS and by the lower concentration of IgG (which had a relative fluorescence increase of 960%), while the worst condition was obtained by the one that used the lower amounts of coupling agents and IgG (with relative increase in the fluorescence of 80%). All stages of the electrode modifications were monitored by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The electrochemical analysis for the vitreous carbon electrode modified with amino functionalized polypyrrole showed no differences compared to the clean electrode. However, after the immobilization of CdTe carboxylate QDs, the results showed a decrease in the charge transfer process. Subsequently, the cyclic voltammetry in the presence of the IgG antibody also presented a decrease and a gradual displacement of the cathodic and anodic peak currents, indicating the immobilization of this biomolecule on the electrode surface. EIS analyses were consistent with those performed by VC. A correlation was observed between the evaluations in the electrode and the FMA, indicating that the best condition in the FMA is an effective choice for the platform. The results also indicated that QDs and IgGs were preferably immobilized by covalent coupling. Preliminary evaluations have also indicated that the platform, modified by amino functionalized pyrroles and carboxyl-coated QDs, was able to detect anti-IgG in the range of ng mL-1, showing to be a potential platform for the detection of diagnostic biomarkers.