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[EN] 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., This work was financially supported by Science & Technologies Facilities Council, EPSRC (EP/K017160/1, EPGO3768X/1, EP/L016354/1, EP/H04630511) and the ERC Consolidator grant scheme (617107 O2SENSE to Sofia Pascu) and University of Bath. Dr David G. Calatayud thanks the Fundación General CSIC for funding (ComFuturo Program). We thank Drs James Tyson, Vincenzo Mirabello and Justin O'Byrne (Bath University) for their collaborative support, helpful discussions and particularly for the assistance with initial batches of GO and thermally reduced GO synthesis, PXRD and Raman spectroscopy.

Hypoxia selectivity of new gallium-68 bis-(thiosemicarbazones) synthesised via microwave heating were investigated., We report the microwave synthesis of several bis(thiosemicarbazones) and the rapid gallium-68 incorporation to give the corresponding metal complexes. These proved kinetically stable under ‘cold’ and ‘hot’ biological assays and were investigated using laser scanning confocal microscopy, flow cytometry and radioactive cell retention studies under normoxia and hypoxia. 68Ga complex retention was found to be 34% higher in hypoxic cells than in normoxic cells over 30 min, further increasing to 53% at 120 min. Our data suggests that this class of gallium complexes show hypoxia selectivity suitable for imaging in living cells and in vivo tests by microPET in nude athymic mice showed that they are excreted within 1 h of their administration.

[EN] Molecular imaging has become a powerful technique in preclinical and clinical research aiming towards the diagnosis of many diseases. In this work, we address the synthetic challenges in achieving lab-scale, batch-to-batch reproducible copper-64- and gallium-68-radiolabelled metal nanoparticles (MNPs) for cellular imaging purposes. Composite NPs incorporating magnetic iron oxide cores with luminescent quantum dots were simultaneously encapsulated within a thin silica shell, yielding water-dispersible, biocompatible and luminescent NPs. Scalable surface modification protocols to attach the radioisotopes Cu (t=12.7 h) and Ga (t=68 min) in high yields are reported, and are compatible with the time frame of radiolabelling. Confocal and fluorescence lifetime imaging studies confirm the uptake of the encapsulated imaging agents and their cytoplasmic localisation in prostate cancer (PC-3) cells. Cellular viability assays show that the biocompatibility of the system is improved when the fluorophores are encapsulated within a silica shell. The functional and biocompatible SiO matrix represents an ideal platform for the incorporation of Cu and Ga radioisotopes with high radiolabelling incorporation., The authors are grateful for the helpful contributions, discussions and training received from the following: Professors Jason Lewis, Stephen Faulkner, and Philip Blower (MSKCC New York, Oxford and London KCL, respectively) and Drs H. Betts and P. Waghorn (Oxford and Harvard, respectively). The authors would like to thank Drs Paul Burke and Patrick Riss (Wolfson Brain Imaging Centre, Addenbrooke’s Hospital, Cambridge) for provision of 64Cu and training in this facility. Dr. Adrian T. Rogers (Microscopy and Analysis Suite), Prof. Rex M. Tyrrell (Department of Pharmacy & Pharmacology at the University of Bath), Rebecca Diment (Bath), Dan Lee (Oxford), Drs Justin P. O’Byrne and Stephen E. Flower are thanked for their invaluable contribution to preliminary aspects of this work. We thank Dr Michael W. Jones (Oxford) for assistance with the acquisition of some of the fluorescence microscopy images, Professor Quentin Pankhurst (UCL) for assistance with magnetic measurements and Dr N. Rees (Oxford) for paramagnetic NMR work. Dr Petra Cameron is thanked for assistance with early-stage tests on a proof-of-principle quantum dot encapsulation. The authors thank the Royal Society, TSB, EPSRC and MRC for funding, also the EPSRC Mass Spectrometry service (Swansea). The team was also funded by the European Commission FP7 Programme through the Marie Curie Initial Training Network PROSENSE (grant no. 317420, 2012–2016) and SIP also thanks the European Commission for an ERC Consolidator Grant (O2SENSE Program 617107, 2014–2019).

Functional porphyrins have attracted intense attention due to their remarkably high extinction coefficients in the visible region and potential for optical and energy-related applications. Two new routes to functionalised SWNTs have been established using a bulky Zn-II-porphyrin featuring thiolate groups at the periphery. We probed the optical properties of this zinc(II)-substituted, bulky aryl porphyrin and those of the corresponding new nano-composites with single walled carbon nanotube (SWNTs) and coronene, as a model for graphene. We report hereby on: i) the supramolecular interactions between the pristine SWNTs and Zn-II-porphyrin by virtue of pi-pi stacking, and ii) a novel covalent binding strategy based on the Bingel reaction. The functional porphyrins used acted as dispersing agent for the SWNTs and the resulting nanohybrids showed improved dispersibility in common organic solvents. The synthesized hybrid materials were probed by various characterisation techniques, leading to the prediction that supramolecular polymerisation and host-guest functionalities control the fluorescence emission intensity and fluorescence lifetime properties. For the first time, XPS studies highlighted the differences in covalent versus non-covalent attachments of functional metalloporphyrins to SWNTs. Gas-phase DFT calculations indicated that the Zn-II-porphyrin interacts non-covalently with SWNTs to form a donor-acceptor complex. The covalent attachment of the porphyrin chromophore to the surface of SWNTs affects the absorption and emission properties of the hybrid system to a greater extent than in the case of the supramolecular functionalisation of the SWNTs. This represents a synthetic challenge as well as an opportunity in the design of functional nanohybrids for future sensing and optoelectronic applications., S.I.P. and S.W.B. thank The Royal Society and STFC for funding. B.Y.M. thanks the University of Bath for a studentship (ORS). J.B.d.l.S. acknowledges support for a European Union Marie Curie Career Integration Grant. Dr. Rory L. Arrowsmith is thanked for the initial stages of the DFT calculations of the ZnII-porphyrin. Dr. Amy Kieran is thanked for initial experiments in porphyrin synthesis. The authors thank EPSRC National Service for computational chemistry software and High Performance Computational facilities at Imperial College London for support and computational facilities. Professors Jeremy K. M. Sanders and Paul Raithy are acknowledged for training, helpful discussions in supramolecular chemistry, and porphyrin supramolecular chemistry, as well as mentorship to S.I.P. and her group. Dr. Gabriele Kociok-Kohn is thanked for assistance with X-ray diffraction. B.J.H. and S.I.P. thank EPSRC for funding from the CDT in Sustainable Chemical Technologies. The S.I.P. group thanks the EPSRC for funding, as a member of the Centre of Graphene Science. The authors thank EPSRC National Service for Mass Spectrometry at Swansea and EPSRC National Service for Crystallography at Southampton for data collection. The authors also acknowledge the ERC for the Consolidator Grant O2SENSE., info:eu-repo/semantics/publishedVersion

This study reports on the supramolecular assemblies formed between planar carbon systems (PCSs) such as thermally reduced graphene oxide (TRGO) and its small-molecule model system coronene and a series of d- and l-α amino acid derivatized naphthalenediimides (NDIs) where the halogen substituents (X = F, Cl, Br, I) are varied systematically. Confocal fluorescence microscopy of NDIs, NDI•coronene, and NDI•TRGO complexes is performed proving the uptake and stability of such complexes in the cellular environment and suggesting their potential as prostate cancer imaging agents. 1H NMR and UV-vis spectroscopy studies support the formation of charge transfer complexes whereby the increasing polarizability and general electronegativity of the aryl halide substituted at the NDI periphery influence the magnitude of the association constants in the ground state between NDI and coronene. Complexation between NDIs and PCSs also results in stable photoexcited assemblies within the solution (coronene) as well as the dispersed phased (TRGO). Fluorescence emission titrations and 2-photon time correlated single photon counting measurements suggest the existence of dynamic quenching mechanisms upon the excitation of the fluorophore in the presence of the carbon substrates, as these methods are sensitive proves for the subtle changes in the NDI environment. The series of halogenated species used exerts supramolecular control over the degree of surface assembly on the TRGO and over the interactions with the coronene molecule, and this is of relevance to the assembly of future biosensing platforms as these materials can both be viewed as congeners of graphene. Finally, MTT assays carried out in PC-3 cells demonstrate that the stable noncovalent functionalization of TRGO and coronene with either l or d NDIs remarkably improves the cellular viability in the presence of such graphene-like materials. These phenomena are of particular relevance for the understanding of the direct donor-acceptor interactions in solutions which govern the design of nanomaterials with future biosensing and bioimaging applications.

The area of biomedical imaging is fast becoming an active focus for the utilization of graphene within a variety of imaging modalities. Graphene can be oxidized to produce a material with a high degree of functionality and has led to its expansion as a platform for the immobilization of fluorescent and radiolabeled molecules. Its large surface area has allowed graphene and its oxides to be modified with a variety of molecules that enhance biocompatibility, selectivity, and therapeutic potential. This chapter highlights recent developments in the use of targeted fluorogenic or radiolabeled graphene materials that can be used to image cancers via fluorescence, positron emission tomography, and single-photon emission computed tomography modalities. Key emphasis is placed on the nanocomposites that are designed to provide additional therapeutic effects. The capacity of these composites to be internalized by cells and tumors is discussed to appreciate the future perspective of graphene and its congeners as therapeutic multimodal imaging agents.