Synthesis of Si/SiO2 core/shell fluorescent submicron-spheres for monitoring the accumulation of colloidal silica during the growth of diatom Chaetoceros sp.

Marine diatoms play a very crucial role in carbon export, and current food-web become an important factor global silica cycle. This then has made the mechanism of their biosilicification interesting to be research subject. The classical theory states that metabolism been originated from absorption silicate ions, which might not give suitable explanation for solid silicification. In this study, mono-disperse Si/SiO2 fluorescent submicron-spheres were synthesized aqueous solution, applied monitoring extracellular accumulation Chaetoceros sp. diatom. submicron particles emitted light-blue color with spectrum centered at 440 nm under excitation 365 UV light, similar typical excitation/emission pair DAPI fluorophore (excitation/emission: 358 nm/461 nm). fluorescence-microscopic investigation showed delocalized on diatoms’ surface increased silicic-acid-level surrounding microalgae. As consequence, growth rate as concentration SiO2 was 120 mg/L, reached 1.5 times higher than calculated F2 media. study only introduces new aspect microalgae corresponding cycle, but also presents new-type culturing media using nanoparticles diatom cultivation, increases artificial diatom-culturing further applications.