Thèses sur le sujet « Points quantiques – Synthèse (chimie) »
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Mabrouk, Salima. « Synthèse par voie colloïdale et étude des propriétés optiques et structurales de nanocristaux ternaires ZnSeS dopés ». Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0169.
Texte intégralIn recent years, ternary QDs have experienced an exponential development thanks to their properties, especially their photoluminescence, which can be controlled not only by their size but also by their composition. As part of this thesis, we developed a new "green" synthesis in aqueous media of ZnSeS-doped ternary QDs and we studied the effect of the variation of the dopant (Mn2+, Cu2+, or Cu2+/Al3+) as well as its localization (in the core or in the shell) on their optical and structural properties. The first part of this work describes the synthesis of ZnSeS:Mn ternary QDs and ZnSeS:Mn/ZnS core/shell using 2-MPA as a ligand. The results obtained show that these nanocrystals can be prepared with quantum yields of 22% and 41%, respectively. These QDs have shown excellent photostability under UV irradiation and can easily be transferred to the organic phase using the hydrophobic octanethiol ligand without altering their optical properties. Subsequently, core/shell ZnSeS/ZnS:Cu/ZnS QDs for which the Cu dopant is introduced into the first shell were prepared using 3-MPA as a ligand. Excellent (photo)stability in the presence of air and oxygen was observed. ZnSeS/ZnS:Cu/ZnS core/shell QDs have a 20% photoluminescence quantum yield and have been used as photoluminescent probes for the detection of Pb2+ ions in aqueous media. A selective extinction of the photoluminescence emission in the presence of Pb2+ ions was observed. Finally, Cu and Al co-doped QDs, ZnSeS/ZnS:Cu/ZnS:Al/ZnS (first shell doped with Cu2+ and second shell doped with Al3+) were prepared. Co-doping allows the improvement of the optical properties, including quantum efficiency (up to 32%) as well as the photoluminescence lifetime of Cu-doped QDs
Mrad, Maroua. « Nouveaux procédés de synthèse en milieu aqueux de quantum dots ternaires AgInS₂ (AIS) et quaternaires AgInS₂/ZnS (AIZS). Dopage de ces nanocristaux par Ni²⁺ ou Co²⁺. Application à la photocatalyse hétérogène ». Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0119.
Texte intégralQuantum dots (QDs) have high potential for biological detection, photovoltaics and catalysis due to their unique photophysical properties. The most studied semiconductors contain heavy metals such as cadmium and lead and their fields of application are very limited. As part of this thesis, we developed new aqueous synthesis processes for ternary QDs AgInS₂ and quaternary AgInS₂/ZnS and studied their doping by the Ni(+2) and Co(+2) cations to prepare nanocrystals with fluorescent and magnetic properties. We first optimized the synthesis of AIZS QDs in aqueous media using 3-MPA as ligand and produced nanocrystals with a fluorescence quantum yield of 65%. Then, the doping of these nanocrystals by cations Ni(2+) and Co(2+) was studied. A drop in quantum fluorescence efficiency is observed after doping. The best magnetic properties were observed at low temperature (10 K) and the magnetization values increase with the dopant concentration. The AIZS QDs have been associated with the ZnO nanorods by heterojunction to form a good photocatalyst ZnO/AIZS(10%) which degrades 98% of the Orange II in visible during 90 min under intensity 40 W/cm². This material can be reused, its photocatalytic activity only slightly decreases after 8 cycles (91% photodegradation)
Alterary, Seham. « Synthèse, caractérisation et fonctionnalisation de CdS et de suspensions magnétiques collïdales en vue d'application biomolécules ». Paris 7, 2008. http://www.theses.fr/2008PA077230.
Texte intégralSemiconductor quantum dots (QDs) are a new generation of inorganic probes with advantageous properties over traditional organic probes for biological applications. A major hurdle in the use of QDs for biology is the inability of the hydrophobically synthesized QDs to interface with aqueous environments. In the first part of this dissertation we describe the synthesis of water-soluble CdS QDs end-capped with N-hydroxysuccinimide ester groups, with narrow size distribution. These CdS QDs are synthesized in polyol medium using terthiophene dicarboxylic acid as a stabilizer. The structure of the hybrid product was investigated by TEM, XRD, optical and FTIR spectroscopy. The modifîed nanoparticles consist of a few tens of oligothiophène units attached to the CdS core. The free carboxylic end groups were transformed into 7V-hydroxysuccinimidyl ester and were further cross-linked with biotin and avidin. Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy results indicate successful modification of CdS QD surfaces. The second part, describes the synthesis and the characterization of hybrid magnetic core-shell structures. The Stöber method bas been adopted to prepare hybrid core-shell particles by coating the surfaces of monodisperse magnetic emulsion with uniform silica shells. The Stöber method has been adopted to prepare hybrid core-shell particles by coating the surfaces of monodisperse magnetic emulsion with uniform silica shells. The coated particles have been characterized by electron microscopy (TEM), XPS spectroscopy and IR and showing a core shell structure with a uniform layer of silica
Henry, Étienne. « Auto-assemblages nanostructurés à base de lipides, d'actine et de quantum dots : synthèse, structure et propriétés photophysiques ». Rennes 1, 2007. http://www.theses.fr/2007REN1S166.
Texte intégralTwo nanostructured self-assemblies, with and without quantum dots, were obtained by the synchronization of the growth of actin filaments and the layer stacking of lipidic membranes. A broad panel of techniques (X-rays diffraction, transmission electronic microscopy and optical microscopy) and an important instrumental development allowed to study and understand the growing dynamic of these matrices, in order to control their nanostructuration. A fluorescence micro-spectrometer has been developed to study the fluorescence of the matrix decorated by quantum dots. New photophysic properties has been characterized and are due to the nanostructuration. The new feature of the structures and their biochemical mechanism of organization, open new features in the field of self-assembled materials and nano-photonic
Galiyeva, Perizat. « Doped Ag-In-Zn-S and Ag-In-Ga-Zn-S QDs : synthesis and potential as dual-modality probes for magnetic resonance and fluorescence imaging of cells ». Electronic Thesis or Diss., Université de Lorraine, 2021. http://www.theses.fr/2021LORR0118.
Texte intégralSince fluorescence imaging (FI) and magnetic resonance imaging (MRI) are among the most effective diagnostic tools, QDs with fluorescent and magnetic properties are of great interest as dual-modal probes. In this work, undoped and doped Ag-In-Zn-S (AIZS) and Ag-In-Ga-Zn-S (AIGZS) QDs were synthesized and investigated as bimodal probes for FI and MRI. Highly fluorescent AIZS QDs were prepared in organic media using DDT and OAm as capping ligands. Mn:AIZS QDs showed paramagnetic and superparamagnetic properties. AIZS and Mn:AIZS QDs were also transferred into aqueous phase using the amphiphilic PMAO polymer. Further, Mn, Gd or Fe-doped AIZS QDs were prepared in aqueous media, showed low cytotoxicity toward KB cells, and demonstrated potential as fluorescent probes for FI. Finally, AIGZS and Mn:AIGZS QDs, synthesized via a novel single precursor thermal decomposition method, showed high fluorescence and paramagnetic/superparamagnetic properties. Mn-doped aqueous transferred AIGZS QDs increased contrast in both T1-weighted and T2-weighted images with increasing in Mn loading
Loczechin, Aleksandra. « Les nanomatériaux en carbone : des alternatives antibactériennes et antivirales ». Thesis, Lille 1, 2019. http://www.theses.fr/2019LIL1I117.
Texte intégralIncreasing antibiotic resistance and limited development of new drugs necessitate the search for alternative strategies to eradicate bacterial infections. Similar problems are faced in the development of antiviral therapeutics, due to the constant emergence of new viruses and their ability to escape therapy by genetic mutations. This work investigates the potential antibacterial and/or antiviral activity of carbon-based nanostructures such as diamond nanoparticles and carbon quantum dots (CQDs) as well as reduced graphene oxide (rGO) in combination with cryogels. CQDs formed by hydrothermal synthesis from 4-aminophenylboronic acid as the carbon precursor showed to be efficient in the inhibition of the viral attachment of human coronavirus HCoV-229E-Luc to cells with an EC50 of 5.2±0.7 µg mL-1. Mechanistic studies suggest that the CQDs are acting at the early stage of virus infection as well at the viral replication step. In parallel, we took advantage of the multivalent character of CQDs as well as nanodiamonds and modified them with short synthetic antimicrobial peptides (AMPs). Tests of these nanostructures against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli pathogens showed increased antibacterial activity when compared to AMPs alone. In the case of rGO combined with cryogels loaded with AMPs, bacterial eradication was achieved efficiently and on-demand using near-infrared light as external trigger to release AMPs
Bogicevic, Alexandra. « Synthèse colloïdale de structures hybrides or/quantum dots ». Electronic Thesis or Diss., Université Paris sciences et lettres, 2021. http://www.theses.fr/2021UPSLS092.
Texte intégralColloidal semiconductor nanocrystals, also known as quantum dots (QDs), have exceptional optical properties, such as high absorption cross section and quantum yield. Their emission spectra can be tuned by changing their size, their shape or composition. Recently, our group reported the plasmonic coupling of unique QD emitters embedded in silica coated with a gold nanoshell with a Purcell factor of 6. The resulting emitters showed enhanced photostability and reduced blinking rates.In this thesis, we explore synthesis and optical properties of similar objects containing not one but hundreds of QDs in their core (superparticles).We first synthesize CdSe/CdS/ZnS core/multishell QDs and assemble them into aggregates of controlled sizes by emulsion/evaporation. The aggregates are then coated with a silica shell (Stöber process) and with a gold nanoshell using a deposition process.The optical properties of QD aggregates with and without gold shells are addressed. These objects exhibit high quantum efficiency, as well as stable and Poissonian emission at room temperature. In addition, we demonstrate a Förster-type resonance energy transfer (FRET) between neighboring QDs inside the aggregates. We also prove that polyvinylpyrrolidone (PVP) can be used to regulate both the reduction rate of gold and the morphology of the gold nanoshell.The second objective is to transpose this synthesis onto 2D semiconductor nanocrystals called nanoplatelets (NPLs) which exhibit particular emission polarization properties thanks to their anisotropic shape. To preserve this anisotropy throughout the synthesis process of the gold nanoshells, a supplementary extension step has to be conducted on these NPLs
Merheb, Melissa. « Une approche universelle d'assemblage dirigé de nanoparticules dans des microstructures polymères 1D, 2D et 3D ». Electronic Thesis or Diss., Troyes, 2022. http://www.theses.fr/2022TROY0013.
Texte intégralThe controlled assembly of nanoparticles (NPs) on 3D micropatterns and over a large surface is a promising method for the creation of structured materials with new properties. In this context, the combination of lithography with colloidal deposition has attracted much attention during the last decade due to the advantages offered by both approaches. In this thesis, we have developed a versatile method allowing the control of the assembly of NPs whatever their nature, size and shape. This approach is based on the functionalization of a photopolymer in order to give it positive charges allowing it, after two photon photopolymerization (2PP) step, to attract negatively charged NPs, due to electrostatic interactions. Studying the reactivity of the photopolymer and both optical and structural properties of the assemblies enabled us to optimize the photochemical stability in 2PP, improve the reproducibility of the process, extend the functionalization technique to a large number of amines and acrylic monomers and provide a better understanding of the functionalization mechanism. At the same time, we have proposed a new functionalization approach that consists of treating the polymerized surface with amines. The advantage of this approach is the possibility of obtaining an assembly of NPs on large surfaces produced by photopolymerization at 1 or 2 photons which overcomes the constraints associated with the prior functionalization of the monomer
Parola, Stéphanie. « Synthèse et caractérisations de matériaux composites à base de nanocristaux de Ge pour des applications optroniques ». Phd thesis, Université de Strasbourg, 2012. http://tel.archives-ouvertes.fr/tel-00762352.
Texte intégralKharin, Alexander. « Group IV nanoparticles for cell imaging and therapy ». Thesis, Lyon, 2016. http://www.theses.fr/2016LYSE1032/document.
Texte intégralBiomedicine and biophotonics related businesses are currently growing at a breathtaking pace, thereby comprising one of the fastest growing sectors of innovative economy. This sector is truly interdisciplinary, including, very prominently, the development of novel nanomaterials, light sources, or novel device/equipment concepts to carry out photon conversion or interaction. The great importance of disease diagnosis at a very early stage and of the individual treatment of patients requires a carefully targeted therapy and the ability to induce cell death selectively in diseased cells. Despite the tremendous progress achieved by using quantum dots or organic molecules for bio-imaging and drug delivery, some problems still remain to be solved: increased selectivity for tumor accumulation, and enhancement of treatment efficiency. Other potential problems include cyto- and genotoxicity, slow clearance and low chemical stability. Significant expectations are now related to novel classes of inorganic materials, such as silicon-based or carbon-based nanoparticles, which could exhibit more stable and promising characteristics for both medical diagnostics and therapy. For this reason, new labeling and drug delivery agents for medical application is an important field of research with strongly-growing potential.The 5 types of group IV nanoparticles had been synthesized by various methods. First one is the porous silicon, produced by the electrochemical etching of bulk silicon wafer. That well-known technique gives the material with remarkably bright photoluminescence and the complicated porous structure. The porous silicon particles are the agglomerates of the small silicon crystallites with 3nm size. Second type is 20 nm crystalline silicon particles, produced by the laser ablation of the bulk silicon in water. Those particles have lack of PL under UV excitation, but they can luminesce under 2photon excitation conditions. 3rd type of the particles is the 8 nm nanodiamonds
Kolmykov, Oleksii. « Synthèse en milieu aqueux de nanocristaux de semi-conducteurs via des procédés microfluidiques ». Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0090/document.
Texte intégralIn recent years, microfluidics has become an attractive technology for the continuous flow synthesis of colloidal nanocrystals. This technology allows a good control of the synthesis parameters, a good reproducibility and the possibility of the application on a large scale. In a first part, we have developed continuous and ecological syntheses of the ZIF-8 crystals for the large scale, either with a monophasic or a biphasic flow (water/alkane). The microfluidic technology allows the fast synthesis (10 min) of ZIF-8 crystals over a wide size range (from ca. 300 to 900 nm) simply by varying the experimental parameters (flow rates, temperature,…). ZIF-8 crystals with the stable rhombic dodecahedron shape, of sodalite structure and with a high specific surface area (ca. 1700 m2.g-1) were obtained. Next, the catalytic properties of ZIF-8 crystals were evaluated. These particles were demonstrated to be an efficient heterogeneous catalyst for the Knoevenagel synthesis of α,β-unsaturated cyanoesters and of 3-cyanocoumarins using 2-hydroxy aromatic aldehydes and ethyl cyanoacetate as starting materials (yields ranging from 89 to 95%). The ZIF-8 particles can be recycled at least five times with negligible changes in catalytic performances. In the second part, we synthesized the Mn2+ or Cu+-doped CdS QDs coated with a ZnS shell in a tubular microreactor using a monophasic or a biphasic flow (water/alkane). Various experimental parameters (time, temperature, pH, molar ratio, concentration and nature of the starting materials) were evaluated to optimize the optical properties of the dots. The obtained Mn2+ doped CdS QDs exhibited a photoluminescence emission related to the 4T1 → 6A1 transition with quantum yields higher than 10%. The introduction of a ZnS shell with the monophasic flow allows to improve the optical properties and to reduce the surface defects of the 6% Mn:CdS/ZnS QDs (strong emission at 590 nm and quantum yields of ca. 20%). The introduction of a ZnS shell on the surface of Cu doped CdS QDs does not significantly improve the quantum yields. Finally, the synthesis of Mn2+-doped ZnS QDs with monophasic or biphasic flow (water/alkane) was developed. The dots have a photoluminescence quantum yield of 13% if they are prepared in a monophasic water flow
Jamal, Al Dine Enaam. « Synthèse et caractérisation des nanoparticules intelligentes ». Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0054/document.
Texte intégralOne of the major challenges in nanomedicine is to develop nanoparticulate systems able to serve as efficient diagnostic and/or therapeutic tools against sever diseases, such as infectious or neurodegenerative disorders. To enhance the detection and interpretation contrast agents were developed to increase the signal/noise ratio. Among them, Superparamagnetic Iron Oxide (SPIO) and Quantum Dots (QDs) nanoparticles (NPs) have received a great attention since their development as a liver contrasting agent 20 years ago for the SPIO. Furthermore, their properties, originating from the nanosized dimension and shape, allow different bio-distribution and opportunities beyond the conventional chemical imaging agents. The opportunity to coat those biocompatible NPs by a polymer shell that can ensure a better stability of the materials in the body, enhance their bio-distribution and give them new functionalities. It has appeared then that they are very challenging for medicinal applications. In this work, we have developed new responsive SPIO and QDs based NPs that are able to carry the anticancer drug doxorubicin (DOX) and release it in physiological media and at the physiological temperature. Two families of NPs were synthesized, the first one consist in superparamagnetic Fe3O4 NPs that were functionalized by a biocompatible responsive copolymer based on 2-(2-methoxy) ethyl methacrylate (MEO2MA), oligo (ethylene glycol) methacrylate (OEGMA). The second family consists in the ZnO NPs coated by the same copolymer. For the first time, P(MEO2MAX-OEGMA100-X) was grown by activator regenerated by electron transfer–atom radical polymerization (ARGET-ATRP) from the NPs surfaces by surface-initiated polymerization. The core/shell NPs were fully characterized by the combination of transmission electron microscopy (TEM), thermogravimetric analysis (TGA), and by the physical properties of the nanostructures studied. We demonstrate the efficiency of the ARGET-ATRP process to graft polymers and copolymers at the surface of Fe3O4 and ZnO NPs. The influence of the polymer chain configuration (which leads to the aggregation of the NPs above the collapse temperature of the copolymer (LCST)) was studied. We have demonstrated that the magnetic properties of the core/shell Fe3O4-based nanostructures were only influenced by the amount of the grafted polymer and no influence of the aggregation was evidenced. This simple and fast developed process is efficient for the grafting of various co-polymers from any surfaces and the derived nanostructured materials display the combination of the physical properties of the core and the macromolecular behavior of the shell. The drug release experiments confirmed that DOX was largely released above the co-polymer LCST. Moreover, the cytocompatibility test showed that those developed NPs do not display any cytotoxicity depending on their concentration in physiological media. From the results obtained, it can be concluded that the new nanomaterials developed can be considered for further use as multi-modal cancer therapy tools
Noblet, Thomas. « Etude optique du couplage vibroélectronique à l'interface entre boîtes quantiques semiconductrices et molécules organiques ». Thesis, Université Paris-Saclay (ComUE), 2019. http://www.theses.fr/2019SACLS272.
Texte intégralThe different physico-chemical processes occurring within semiconductor quantum dots (QDs) give rise to a new class of fluorescent probes and a wide range of applications in catalysis, molecular recognition and imaging. Within these luminescent nanoparticles, the quantum confinement of electrons, which leads to their very special excitonic structure, allows us to benefit from both their absorption and emission optical properties, with the specific aim of fostering the detection and the identification of the chemical species located in their direct environment. Within this framework, we were interested in 3 to 4-nm-sized QDs composed of ternary alloys of cadmium, telluride and sulfur, and functionalized by mercaptocarboxylic ligands. In order to determine their structural, chemical and optoelectronic properties, we first characterized them thanks to several experimental techniques: electron microscopy, zeta potentiel measurements, dynamic light scattering analysis, X-ray, UV-visible and fluorescence spectroscopies. This enabled us to deduce the chemical composition of the nanocrystals, their crystal structure, size, size-dispersion, the chemical composition of their ligands, the eigenenergies of their electronic states, their transition dipole moments and absorption cross-sections. Given all those results, we succeeded in deriving an analytical model of the QD dielectric susceptibility and extracting in this way their linear response function. Then, we optimized the chemical synthesis of nanostructured interfaces made of QDs and various molecular species through the use of flat solid substrates of silicon, glass and calcium fluoride functionalized with organosilanes. These substrate/QDs/molecules interfaces were studied by linear UV-visible absorption spectroscopy and by sum-frequency generation non-linear optical spectroscopy (SFG). The former allowed us to determine the surface density of the deposited QDs and to characterize their stability over time, while the later, which combines two visible and infrared lasers, enabled us to identify the vibrational signature of the QD ligands. Thanks to those samples probed by two-colour SFG spectroscopy, we therefore shew the existence of a vibroelectronic coupling between QDs and their molecular surroundings. Especially, we demonstrated that the vibration amplitudes associated to the molecular modes of the QD ligands and the organosilanes grafted on the substrates are maximum when the QDs are excited by visible light into their first excitonic state. This experimental demonstration is further supported by theoretical considerations: Feynman diagrams in Matsubara imaginary-time representation were used to determine the analytical expression of the second-order nonlinear susceptibility of the QD/molecule bipartite system. We thus verified that the hypothesis of a dipolar coupling between QDs and molecules resulted in a modeling of the vibrational SFG response which proved to be in complete agreement with the experimental measurements. Thus, we evidenced the existence of a dipolar vibroelectronic coupling between quantum dots and molecules
Kauffer, Florence-Anaïs. « Synthèse, stabilité et toxicité de quantum dots à coeur CdSe ». Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0006/document.
Texte intégralDue to their unique properties compared to their bulk counterparts, nanomaterials have gained considerable attention, especially in industry and medicine. Their fast development has generated many public concerns, especially because of a lack of knowledge regarding their toxicity. Our project aims to use cadmium selenide (CdSe) as a model material in order to initiate a research aiming at establishing a correlation between the nanoparticles chemical structure, their surface reactivity, their stability and their toxicity. CdSe and alloyed CdSe(S) quantum dots (QDs) were prepared in aqueous phase either at 100°C or under hydrothermal conditions in order to differ solely by their core chemical structure (ternary alloy vs binary semiconductor), while other parameters such as the size, the surface charge or the surface ligand, have been kept constant. Cytotoxicity studies carried out on Escherichia coli have shown that release of Cd2+ played a key role in the toxicity for both QDs. However, alloyed CdSe(S) QDs were also found more stable and less toxic than CdSe nanocrystals. Without disregarding the importance of Cd2+ ions release by the nanoparticles, a correlation between the stability and the production of reactive oxygen species (ROS) showed that toxicity was dependent on QDs photostability. Our study highlights a relationship between the core reactivity, stability and the photo-induced toxicity QD nanoparticles
Nallayagari, Ashwini Reddy. « Carbon quantum dots as electrocatalysts for the oxygen reduction reaction ». Electronic Thesis or Diss., Aix-Marseille, 2022. http://www.theses.fr/2022AIXM0577.
Texte intégralCarbon quantum dots (CQD) are a fascinating nanomaterial and a potential metal-free catalyst for the oxygen reduction reaction to replace the precious Pt-based catalysts in numerous energy applications, such as zinc-air batteries and fuel cells. Detailed performance investigations were conducted with CQD containing different dopants (B, Si, N, S), exploring different synthesis methods and electrochemical tests. The CQD were synthesized from non-toxic precursors mainly through the hydrothermal method. Among the dopants, the B-N co-doped CQD showed the best electrocatalytic activity. Studies were also conducted on composite electrodes with a combination of B-N CQDs and five anion conducting polymers (“ionomers”) with different backbone structures and side chain lengths. The best electrocatalytic activity was observed with ionomers containing the functional ionic group on a long side chain, which provided performances close to commercial benchmark Pt/C cloth
Moquin, Alexandre. « Points quantiques : caractérisation et applications en sciences pharmaceutiques ». Thèse, 2014. http://hdl.handle.net/1866/11758.
Texte intégralMedical imaging based on fluorescence has suffered from the poor photostability and mediocre performance of organic fluorophores. The discovery and subsequent improvements in nanocrystal synthesis and functionalization has greatly benefited the applications in medical imaging and the development of nanocrystal-based sensors for diagnostics. QDs are semi-conductor nanocrystals which have similar sizes as proteins (2-10 nm). They are highly luminescent, and can be made to emit at any desired wavelength by varying their size and composition. The surface of QDs can be easily functionalized with biomolecules. Hence, it is interesting to study how QDs interact in the biological world. Highly luminescent core-shell QDs emitting at different wavelengths were prepared according to our needs. In a first study, the surface of the QDs was modified with various small bi-functional thiolated ligands (carboxylated, aminated and zwitterionic). The modified-QDs of nearly identical sizes were administered in vitro to study the impact of surface charge and cell type on the mode and extent of cell uptake and elimination. Using specific inhibitors of cell uptake we determined which modes contributed to the internalization of the QDs. Endocytosis mediated by lipid rafts represented the predominant pathway for the internalization of QDs. However, other modes contributed to a lesser degree, depending on the surface ligand. We then analyzed the effect of QD agglomeration in cell culture media on its cellular uptake by microglia. Thorough characterization of QD agglomerate size distribution was conducted by asymmetrical flow field-flow fractionation (AF4) with a dynamic light scattering detector. Depending on the type of surface ligand and if serum proteins were present, the agglomeration pattern of the QDs was significantly different. With inhibitors of specific modes of cell uptake, we showed that the size distribution data, obtained by AF4, correlated with the modes of cell uptake. Microglia cells are immune cells of the central nervous system (CNS). They respond to injury or the presence of inflammagens by producing pro-inflammatory cytokine. Inflammation in the CNS may lead to loss of neurons, and can found in many chronic diseases. We were interested in building nanosensors to measure the onset of inflammation. Current methods to study inflammation consist in measuring levels of certain proteins or chemicals released by stressed cell (e.g. Western blot or ELISA assay for IL-1β). Although precise, these methods measure indirectly the activity of the enzyme responsible for releasing IL-1β, i.e. caspase-1. Moreover, these methods cannot be applied to live cells. We designed a sensor based on FRET between a QD and a dye linked by a peptide specifically cleaved by the caspase-1. To induce inflammation, we applied lipopolysaccharides (LPS), which are endotoxins present in Gram negative bacteria responsible for sceptic shock. The LPS form nanoparticles due to their amphiphilicity. The interior hydrophobic regions were used to load hydrophobic QDs, making the LPS luminescent. The microglia internalized LPS-QD predominantly through TLR-4 membrane receptors. We describe how the LPS induce inflammation and demonstrated the functionality of the QD-based sensor. Eventually, the sensor could be used to monitor in real time the action of therapeutics against inflammation.