Living diatoms integrate polysaccharide-Eu3+ complex for UV downconversion

In this work, living diatoms (LDT) were fed Eu3+-complex-polysaccharide aggregates (EIPA), and the living diatoms integrated-EIPAs (LDT-E) in a completely new UV downconversion biophotonic material. The EIPAs were embedded inside siliceous cell walls of living diatoms. When dried, these diatoms (LDT-Es) are luminescent at 612 nm, due to the Eu3+-complex. As UV-downconversion material, LDT-E absorbs UV light in the band of 250–400 nm and converts into useful visible light, thus contributing to UV-protection and potentially to photocurrent generation in photovoltaic devices. This downconversion material from living diatom retains the porous characteristics of the diatom siliceous cells, as well as the diatom organic components. Most important is the absence of a chemical process to generate this biomaterial from natural living diatoms, in order to obtain UV-protection and downconversion.