Organización bio-inspirada y jerarquizada de arquitecturas supramoleculares electroactivas basadas en nanoestructuras de carbono

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Químicas, Departamento de Química Orgánica I, leída el 04-12-2015La nanotecnología, referida a la manipulación de la materia a nivel molecular y supramolecular, es un área emergente con prometedores beneficios para la humanidad.1 En particular, las nanoestructuras de carbono han captado gran atención debido a sus atractivas propiedades electrónicas y mecánicas. Imitar la naturaleza mediante el desarrollo de procedimientos bioinspirados puede ser una interesante estrategia para organizar nanomateriales ricos en carbono con el fin de maximizar sus propiedades optoelectrónicas...Nanotechnology, referring as the manipulation of matter at the molecular and supramolecular scale, is an emerging area with promising benefits for humanity.1 In particular, carbon nanostructures have received a great attention due to their exciting electronic and mechanical properties. Mimicking nature, that is, developing bioinspired procedures, could be one of the most intelligent strategies to organize matter, in particular carbon-rich nanostructures, with the aim of maximizing their fabulous optoelectronic properties...Depto. de Química OrgánicaFac. de Ciencias QuímicasTRUEunpu

Protein-directed crystalline 2D fullerene assemblies

Water soluble 2D crystalline monolayers of fullerenes grow on planar assemblies of engineered consensus tetratricopeptide repeat proteins. Designed fullerene-coordinating tyrosine clamps on the protein introduce specific fullerene binding sites, which facilitate fullerene nucleation. Through reciprocal interactions between the components, the hybrid material assembles into two-dimensional 2 nm thick structures with crystalline order, that conduct photo-generated charges. Thus, the protein-fullerene hybrid material is a demonstration of the developments toward functional materials with protein-based precision control of functional elements

HaloFlippers: A General Tool for the Fluorescence Imaging of Precisely Localized Membrane Tension Changes in Living Cells.

Tools to image membrane tension in response to mechanical stimuli are badly needed in mechanobiology. We have recently introduced mechanosensitive flipper probes to report quantitatively global membrane tension changes in fluorescence lifetime imaging microscopy (FLIM) images of living cells. However, to address specific questions on physical forces in biology, the probes need to be localized precisely in the membrane of interest (MOI). Herein we present a general strategy to image the tension of the MOI by tagging our newly introduced HaloFlippers to self-labeling HaloTags fused to proteins in this membrane. The critical challenge in the construction of operational HaloFlippers is the tether linking the flipper and the HaloTag: It must be neither too taut nor too loose, be hydrophilic but lipophilic enough to passively diffuse across membranes to reach the HaloTags, and allow partitioning of flippers into the MOI after the reaction. HaloFlippers with the best tether show localized and selective fluorescence after reacting with HaloTags that are close enough to the MOI but remain nonemissive if the MOI cannot be reached. Their fluorescence lifetime in FLIM images varies depending on the nature of the MOI and responds to myriocin-mediated sphingomyelin depletion as well as to osmotic stress. The response to changes in such precisely localized membrane tension follows the validated principles, thus confirming intact mechanosensitivity. Examples covered include HaloTags in the Golgi apparatus, peroxisomes, endolysosomes, and the ER, all thus becoming accessible to the selective fluorescence imaging of membrane tension

Repeat protein scaffolds: ordering photo- and electroactive molecules in solution and solid state

The precise control over the organization of photoactive components at the nanoscale is one of the main challenges for the generation of new and sophisticated macroscopically ordered materials with enhanced properties. In this work we present a novel bioinspired approach using protein-based building blocks for the arrangement of photo and electroactive porphyrin derivatives. We used a designed repeat protein scaffold with demonstrated unique features that allow for the control of their structure, functionality, and assembly. Our designed domains act as exact biomolecular templates to organize porphyrin molecules at the required distance. The hybrid conjugates retain the structure and assembly properties of the protein scaffold and display the spectroscopic features of orderly aggregated porphyrins along the protein structure. Finally,we achieved a solid ordered bio-organic hybrid thin film with anisotropic photoconductivity

Electron-deficient fullerenes in triple-channel photosystems

Fullerenes of increasing electron deficiency are designed, synthesized and evaluated in multicomponent surface architectures to ultimately build gradients in LUMO levels with nine components over 350 mV down to -4.22 eV

Highly Ordered n/p-Co-assembled Materials with Remarkable Charge Mobilities

Controlling self-organization and morphology of chemical architectures is an essential challenge in the search for higher energy-conversion efficiencies in a variety of optoelectronic devices. Here, we report a highly ordered donor/acceptor functional material, which has been obtained using the principle of ionic self-assembly. Initially, an electron donor π-extended tetrathiafulvalene and an electron-acceptor perylene-bisimide were self-organized separately obtaining n- and p-nanofibers at the same scale. These complementary n- and p-nanofibers are endowed with ionic groups with opposite charges on their surfaces. The synergic interactions establish periodic alignments between both nanofibers resulting in a material with alternately segregated donor/acceptor nanodomains. Photoconductivity measurements show values for these n/p-co-assembled materials up to 0.8 cm2 V–1 s–1, confirming the effectiveness in the design of these heterojunction structures. This easy methodology offers great possibilities to achieve highly ordered n/p-materials for potential applications in different areas such as optoelectonics and photovoltaics

Protein-Directed Crystalline 2D Fullerene Assemblies

Repeat proteins with engineered tyrosine clamps provide a platform for fullerene assembly into 2D crystalline materials with long range molecular order and photogenerated charge carrier capacity. Thus, the self-assembling hybrid material allows to utilise the innate properties of fullerenes, demonstrating the potential of engineered protein-based functional materials