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[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