Hybrid lanthanide polyoxotungstate core/shell nanoparticles for fluorescence-based bioimaging

Fluorescence bioimaging is a powerful tool in early stage diagnosis of diseases such as cancer or cardiovascular problems. Lanthanide ions have unique properties, which make them suitable for designing fluorescence bioimaging probes. Up until now mostly lanthanides, which emit in a region visible to the human eye, have been explored for this purpose. Creating lanthanide based bioimaging probes, which emit in the near-infrared (NIR) region of the electromagnetic spectrum would be safer for biological tissue and hold other advantages such as better optical imaging resolution. In this project organic-inorganic hybrid lanthanide polyoxometalates will be explored as a class of materials, which could be used for NIR bioimaging. Lanthanide ions are excellent emitters in the NIR region, but they are hard to excite and the emission is easily quenched. As a result, different combinations of lanthanide polyoxometalates and organic ligands will be employed to enhance the luminescence output. Polyoxometalates in which the lanthanide ion is shielded from water molecules will be chosen to reduce quenching effects. Additionally the hybrid polyoxometalates will be encapsulated into a silica shell to make these materials safe for biological applications. In the last stage of the project in vitro tests will be carried out to assess their potential use as fluorescence bioimaging probes.