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Three‐dimensional fluorescent graphene frameworks with controlled porous morphologies are of significant importance for practical applications reliant on controlled structural and electronic properties, such as organic electronics and photochemistry. Here we report a synthetically accessible approach concerning directed aromatic stacking interactions to give rise to new fluorogenic 3D frameworks with tuneable porosities achieved through molecular variations. The binding interactions between the graphene‐like domains present in the in situ‐formed reduced graphene oxide (rGO) with functional porphyrin molecules lead to new hybrids via an unprecedented solvothermal reaction. Functional free‐base porphyrins featuring perfluorinated aryl groups or hexyl chains at their meso‐ and β‐positions were employed in turn to act as directing entities for the assembly of new graphene‐based and foam‐like frameworks and of their corresponding coronene‐based hybrids. Investigations in the dispersed phase and in thin‐film by XPS, SEM and FLIM shed light onto the nature of the aromatic stacking within functional rGO frameworks (denoted rGOFs) which was then modelled semi‐empirically and by DFT calculations. The pore sizes of the new emerging reduced graphene oxide hybrids are tuneable at the molecular level and mediated by the bonding forces with the functional porphyrins acting as the “molecular glue”. Single crystal X‐ray crystallography described the stacking of a perfluorinated porphyrin with coronene, which can be employed as a molecular model for understanding the local aromatic stacking order and charge transfer interactions within these rGOFs for the first time. This opens up a new route to controllable 3D framework morphologies and pore size from the Ångstrom to the micrometre scale. Theoretical modelling showed that the porosity of these materials is mainly due to the controlled inter‐planar distance between the rGO, coronene or graphene sheets. The host‐guest chemistry involves the porphyrins acting as guests held through π‐π stacking, as demonstrated by XPS. The objective of this study is also to shed light into the fundamental localised electronic and energy transfer properties in these new molecularly engineered porous and fluorogenic architectures, aiming in turn to understand how functional porphyrins may exert stacking control over the notoriously disordered local structure present in porous reduced graphene oxide fragments. By tuning the porosity and the distance between the graphene sheets using aromatic stacking with porphyrins, it is also possible to tune the electronic structure of the final nanohybrid material, as indicated by FLIM experiments on thin films. Such nanohybrids with highly controlled pores dimensions and morphologies open the way to new design and assembly of storage devices and applications incorporating π‐conjugated molecules and materials and their π‐stacks may be relevant towards selective separation membranes, water purification and biosensing applications. By introducing a panel of functional porphyrin molecules, new 3D hierarchical structures incorporating reduced graphene oxide can be achieved. The pore size of the framework can be finely tuned and reduced to a sub‐micron scale for the first time by careful selection of the porphyrin. Experimental and theoretical studies proposed that the pore size diminishing was due to strong local interactions between the designed porphyrin and rGO, mediated by donor‐acceptor interactions, which are maintained in the solution and in thin film.

We report on the design and testing of new graphite and graphene oxide‐based extended π‐conjugated synthetic scaffolds for applications in sustainable chemistry transformations. Nanoparticle‐functionalised carbonaceous catalysts for new Fischer Tropsch and Reverse GasWater Shift (RGWS) transformations were prepared: functional graphene oxides emerged from graphite powders via an adapted Hummer's method and subsequently impregnated with uniform‐sized nanoparticles. Then the resulting nanomaterials were imaged by TEM, SEM, EDX, AFM and characterised by IR, XPS and Raman spectroscopies prior to incorporation of Pd(II) promoters and further microscopic and spectroscopic analysis. Newly synthesised 2D and 3D layered nanostructures incorporating carbon‐supported iron oxide nanoparticulate pre‐catalysts were tested, upon hydrogen reduction in situ, for the conversion of CO2 to CO as well as for the selective formation of CH4 and longer chain hydrocarbons. The reduction reaction was also carried out and the catalytic species isolated and fully characterised. The catalytic activity of a graphene oxide‐supported iron oxide pre‐catalyst converted CO2 into hydrocarbons at different temperatures (305, 335, 370 and 405 °C), and its activity compared well with that of the analogues supported on graphite oxide, the 3‐dimensional material precursor to the graphene oxide. Investigation into the use of graphene oxide as a framework for catalysis showed that it has promising activity with respect to reverse gas water shift (RWGS) reaction of CO2 to CO, even at the low levels of catalyst used and under the rather mild conditions employed at atmospheric pressure. Whilst the γ‐Fe2O3 decorated graphene oxide‐based pre‐catalyst displays fairly constant activity up to 405 °C, it was found by GC‐MS analysis to be unstable with respect to decomposition at higher temperatures. The addition of palladium as a promoter increased the activity of the iron functionalised graphite oxide in the RWGS. The activity of graphene oxide supported catalysts was found to be enhanced with respect to that of iron‐functionalised graphite oxide with, or without palladium as a promoter, and comparable to that of Fe@carbon nanotube‐based systems tested under analogous conditions. These results display a significant step forward for the catalytic activity estimations for the iron functionalised and rapidly processable and scalable graphene oxide. The hereby investigated phenomena are of particular relevance for the understanding of the intimate surface morphologies and the potential role of non‐covalent interactions in the iron oxide‐graphene oxide networks, which could inform the design of nano‐materials with performance in future sustainable catalysis applications. New functional two‐dimensional (2D) and three‐dimensional (3D) nanomaterials relevant for sustainable chemistry applications have been designed and tested. This work is of relevance to enhancing our understanding of the role of supramolecular aggregation on nanotechnology and on optimised designs for future materials for energy conversion/storage as a basis for the reverse gas water shift reaction and Fischer Tropsch chemistry.

We report on the design and testing of new graphite and graphene oxide‐based extended π‐conjugated synthetic scaffolds for applications in sustainable chemistry transformations. Nanoparticle‐functionalised carbonaceous catalysts for new Fischer Tropsch and Reverse GasWater Shift (RGWS) transformations were prepared: functional graphene oxides emerged from graphite powders via an adapted Hummer's method and subsequently impregnated with uniform‐sized nanoparticles. Then the resulting nanomaterials were imaged by TEM, SEM, EDX, AFM and characterised by IR, XPS and Raman spectroscopies prior to incorporation of Pd(II) promoters and further microscopic and spectroscopic analysis. Newly synthesised 2D and 3D layered nanostructures incorporating carbon‐supported iron oxide nanoparticulate pre‐catalysts were tested, upon hydrogen reduction in situ, for the conversion of CO 2 to CO as well as for the selective formation of CH 4 and longer chain hydrocarbons. The reduction reaction was also carried out and the catalytic species isolated and fully characterised. The catalytic activity of a graphene oxide‐supported iron oxide pre‐catalyst converted CO 2 into hydrocarbons at different temperatures (305, 335, 370 and 405 °C), and its activity compared well with that of the analogues supported on graphite oxide, the 3‐dimensional material precursor to the graphene oxide. Investigation into the use of graphene oxide as a framework for catalysis showed that it has promising activity with respect to reverse gas water shift (RWGS) reaction of CO 2 to CO, even at the low levels of catalyst used and under the rather mild conditions employed at atmospheric pressure. Whilst the γ‐Fe 2 O 3 decorated graphene oxide‐based pre‐catalyst displays fairly constant activity up to 405 °C, it was found by GC‐MS analysis to be unstable with respect to decomposition at higher temperatures. The addition of palladium as a promoter increased the activity of the iron functionalised graphite oxide in the RWGS. The activity of graphene oxide supported catalysts was found to be enhanced with respect to that of iron‐functionalised graphite oxide with, or without palladium as a promoter, and comparable to that of Fe@carbon nanotube‐based systems tested under analogous conditions. These results display a significant step forward for the catalytic activity estimations for the iron functionalised and rapidly processable and scalable graphene oxide. The hereby investigated phenomena are of particular relevance for the understanding of the intimate surface morphologies and the potential role of non‐covalent interactions in the iron oxide‐graphene oxide networks, which could inform the design of nano‐materials with performance in future sustainable catalysis applications.

The intracellular environment hosts a large number of cancer- and other disease-relevant human proteins. Targeting these with internalized antibodies would allow therapeutic modulation of hitherto undruggable pathways, such as those mediated by protein–protein interactions. However, one of the major obstacles in intracellular targeting is the entrapment of biomacromolecules in the endosome. Here we report an approach to delivering antibodies and antibody fragments into the cytosol and nucleus of cells using trimeric cell-penetrating peptides (CPPs). Four trimers, based on linear and cyclic sequences of the archetypal CPP Tat, are significantly more potent than monomers and can be tuned to function by direct interaction with the plasma membrane or escape from vesicle-like bodies. These studies identify a tricyclic Tat construct that enables intracellular delivery of functional immunoglobulin-G antibodies and Fab fragments that bind intracellular targets in the cytosol and nuclei of live cells at effective concentrations as low as 1 μM. Reliable intracellular delivery of antibodies is one of the grand challenges in biomedical research, with the potential to address unmet clinical needs or to enable basic research. Now, it has been shown that tricyclic peptide complexes can transport functional antibodies into the cytoplasm and nucleus of cells to specifically target intracellular proteins.

This chapter contains sections titled: Introduction Graphene and Graphene‐Based Functional Materials for Biosensing Applications Graphene and Graphene‐Based Materials for Biosensing Applications Graphene and Graphene‐Like Materials for Bioimaging Applications Conclusions

This work describes investigations into novel fluorescent nanohybrids based on carbon nanomaterials for the optical imaging of prostate cancer cells. The synthesis and characterisation of the different components of the nanoprobes are described within each chapter. The cellular response of as-prepared fluorophores, peptide conjugate and nanoprobes was evaluated in PC-3 cells by optical microscopy techniques for the first time. The new fluorescent conjugate synthesised showed targeted behaviour towards prostate cancer cells and the functional hybrids showed promising characteristics as synthetic scaffolds for future imaging nanomaterials. Chapter 1 describes the context of this work, including different imaging modalities applied to the diagnosis, staging and follow-up of prostate cancer. The use of bombesin as a targeting peptide for prostate cancer, and its incorporation in different imaging probes from current state-of the-art is discussed. The use of specific imaging probes as thiosemicarbazonato-based species is described, due to their current importance in tumour hypoxia detection and multimodality imaging potential. Finally, the use of single walled carbon nanotubes as biomedical scaffolds with a special interest in imaging applications is reviewed. Chapter 2 describes synthetic approaches towards novel functional unsymmetrical thiosemicarbazonato metal complexes. The synthesis of functional novel thiosemicarbazides and the formation of the thiosemicarbazone ligands is reported hereby. Several aromatic dicarbonylic starting materials (other than the known acenaphthenequinone) were explored and a panel of new zinc thiosemicarbazonato complexes were obtained and characterised spectroscopically. Chapter 3 contains the synthesis of bifunctional BODIPY derivatives which incorporate a protected amino acid residue. The synthetic approach towards new derivatives with fluorescence emission in the near-infrared region of the spectra is also reported. Chapter 4 describes the methodology towards the incorporation of the new carbon nanomaterial scaffold. The functionalisation of pristine single walled carbon nanotubes and graphene oxide to incorporate linkers in the structure, and the characterisation of the functionalised materials, are given hereby. Chapter 5 contains the synthesis and purification of the targeting peptide and the BODIPY-peptide conjugate involved as key components for the novel nanohybrids. Other nanohybrids containing the BODIPY or gallium thiosemicarbazonato species are also reported. The behaviour of these compounds in living PC-3 cells was evaluated and the cytotoxicity of a selection of compounds determined, for the first time. Chapter 6 provides a summary of the work carried out during this thesis and some proposals for future work arising from the research findings described herein. Chapter 7 contains detailed experimental details and characterisation data for the compounds described. The Appendices provide supporting spectroscopic evidence and X-ray diffraction data for the new compounds synthesised.