New emitting proteins and all-bio matrices for Bio-WLEDs.

ended

The development of eco-friendly sun-like illumination systems is a priority in Europe. Current solutions, White Inorganic Light-Emitting Diodes (WLEDs), feature excellent efficiency and stability values but rely on rare earth and their production involves an increasing economic and ecological cost. Bio-Hybrid WLEDs (Bio-WHLEDs) represent an environmentally sustainable and cost-effective alternative. They use Fluorescent Proteins (FPs) embedded into a synthetic polymer matrix and act as the color down-converting coating. Bio-WHLEDs are currently limited to low power applications because the continued excitation of FPs promotes its denaturation. This is due to the synthetic nature of the polymeric packaging and of the type of FPs used (generally variants of Green Fluorescent Protein (GFP)). Despite the well-known brightness of such proteins, they have evolved as genetic reporters and not as stable photo-converting materials. In this project, we aim to design, produce and exploit improved matrixes and proteins for the new generation of all bio-based color down-converting coating. To tackle the first limitation of current Bio-WHLEDs, we propose the encapsulation of FPs into marine polysaccharide-based packaging matrices such as bio-doped alginate/ ulvan microparticles. Since the interior of these particles offers a crowded environment more similar to a natural protein surrounding, they are supposed to reduce the thermal stress and increase the photostability of the FPs. To tackle the second limitation, we propose the replacement of GFP-based proteins by Phycobiliproteins (PBPs). PBPs have evolved in nature as light-harvesting antennas in cyanobacteria, being resistant to extreme conditions (high temperature, constant illumination, high concentrations), but emit light only above 550 nm. To give a new twist in originality we propose the use of error-prone PCR and selective evolution to modify PBPs characteristics to obtain red-, green- and orange- emissions