PhOton Piling in UPconverting lanthanide clusters – POPUP

The POPUP project aims at developing new heteropolynuclear complexes based on lanthanide ions for upconversion (UC) at the molecular scale in solution. The UC phenomenon allows to obtain a light emission at higher energy than the excitation, offering a spectral signature free of interference such as auto-fluorescence of samples or spectral overlap between excitation and emission.
Although the UC phenomenon has been demonstrated since the 1960's, it remained until recently confined to the fields of solid state chemistry or nanoparticles. The molecular approach, which appeared only 10 years ago, is confronted with many difficulties related to the trapping of luminescence in solution. Developing efficient systems at the molecular scale remains a challenge for coordination chemistry, but would allow a better control of the composition of the systems and their toxicity for bio-analytical applications.
POPUP plans to develop heteropolynuclear complexes in which the elemental lanthanide composition will be tuned to optimize short-range intramolecular energy transfers and lead to a UC that rivals solid compounds or nanoparticles. POPUP aims to understand the phenomena leading to cluster formation, to better understand their synthesis and to lead to pre-organized assemblies in which the numerous lanthanide ions would be in close proximity, allowing optimized energy transfers and efficient conversion.
Although POPUP is based on a fundamental approach, the applications of such systems would be numerous, ranging from luminescent labeling for microscopy imaging, biological analysis, improvement of the efficiency of photovoltaic cells, to anti-counterfeiting inks.