In recent decades, the demand for biomedical imaging tools has grown very rapidly as a key feature for biomedical research and diagnostic applications. The use of imaging techniques has become a powerful strategy in preclinical and clinical research aiming towards the diagnosis of many diseases. PET, SPECT, MRI, and confocal fluorescence microscopy are among the main biomedical imaging techniques widely used for tumour imaging either in vivo or in vitro and the combination of these techniques allows for better visualisation of the pathogenic pathways. It has been acknowledged that there is no single modality, available amongst current molecular imaging techniques, capable to acquire alone all of the essential information across length scales of molecules to tissues and organs. Thus, a combination of techniques (‘multimodal imaging’) is an essential tool in imaging at the research stage and in translational studies in a clinical setting. Accordingly, new types of fluorescent labels are currently being investigated and, in this search, this work aims to overcome the limitations of current systems to develop a novel series of inorganic-organic hybrid nanostructures (identified as multimodal nanoceramics) in which different types of nanoparticles with selected optical and/or magnetic properties (Fe₃O₄, MnO, Cd_0.1Zn_0.9Se, SrAlO₄:Eu,Dy) will rationally combine, coated with biocompatible silica or CeO₂ layer and subsequently functionalised with double?Schiff?base ligands containing TSC moieties. The potential of such nanocomposites to act as cellular bioimaging agents are investigated via confocal fluorescence microscopy, UV-Vis and their cellular viability are probed by MTT assays. Cellular viability assays show that the biocompatibility of the system is improved when the fluorophores are encapsulated within a silica or CeO₂ shell.

This work was supported by the Spanish Ministry of Science, Innovation and Universities (MICINN) through the MAT2016-80182-R project. Dr D.G. Calatayud acknowledges the Fundación General CSIC (ComFuturo Program) for the financial support. Dr T. Jardiel also acknowledges the European Science Foundation (ESF) and the Ramon y Cajal Program of MICINN for the financial support. Dr S.I. Pascu thanks the European Commission for an ERC Consolidator Grant (O2SENSE Program 617107, 2014–2019). The authors also thank the Royal Society, TSB, EPSRC and MRC for funding.