Proceedings of nanoGe September Meeting 2015 (NFM15)
Publication date: 8th June 2015
The design and development of novel functional hybrid nanomaterials has gained great momentum in recent years in supramolecular chemistry and nanochemistry.1 Owing to their stability and unique photophysical properties, tuneable with their size, nanoparticles have been intensively investigated over the past decade and found numerous applications within the field of chemistry.2 Indeed, they have been incorporated into photovoltaic and electroluminescent devices, or utilised as luminescent probes for bio-imaging and/or as therapeutic agents.3
The elaboration of systems with multi-modal luminescence has become an unavoidable strategy for imaging, facilitating the monitoring of different simultaneous processes and increasing image resolution.4 Trivalent lanthanides are ideal candidates for the development of particle-based multi-modal luminescent systems. This is due to their unique photophysical properties such as long-lived excited-state lifetimes and narrow, easily recognizable line-like emission bands at long wavelengths in either the visible or near-infrared (NIR) regions.5
With the aim of developing novel probes with a multi-modal luminescence our research was focused on the development of a series of heavy metal free hybrid QD/Ln3+ complexes, emitting in the visible and NIR region. First of all, a family of ternary core/shell QD (InPZnSx/ZnSe/ZnS) have been synthesised using an approach previously developed in our lab,6 and these syntheses were further optimized. This first study allowed the production of particles with emission ranging from 500 to 650 nm and high QY (up to 50%). In parallel a new family of highly luminescent lanthanide complexes were synthesized and studied.7 Finally, the lanthanide complexes were grafted successfully onto the particle surface and the properties of the resulting hybrids were studied. Such tailored hybrids exhibit both particle and intense lanthanide emission enabling thus multi-modal time resolved luminescence.