In vivo doped biosilica from living Thalassiosira weissflogii diatoms with a triethoxysilyl functionalized red emitting fluorophore

Diatoms microalgae represent a natural source of highly porous biosilica shells (frustules) with promising applications in a wide range of technological fields. Functionalization of diatoms' frustules with tailored luminescent molecules can be envisaged as a convenient, scalable biotechnological route to new light emitting silica nanostructured materials. Here we report a straightforward protocol for the in vivo modification of Thalassiosira weissflogii diatoms' frustules with a red emitting organic dye based on thienyl, benzothiadiazolyl and phenyl units. The metabolic insertion of the dye molecules into the diatoms shells, combined with an acidic-oxidative isolation protocol of the resulting dye stained biosilica, represents a novel strategy to develop highly porous luminescent biosilica nanostructures with promising applications in photonics.