title: Titanium uptake and incorporation into silica nanostructures by the diatomPinnulariasp. (Bacillariophyceae).
abstract: Diatoms are an ecologically successful group within the phytoplankton, and their special feature is a biofabricated silica cell encasement called a frustule. These frustules attract interest in material technology, and one potential application is to use them in solar cell technology. The silica frustule with its nanoscaled pattern is interesting per se, but the utility is enhanced if we succeed in incorporating other elements. Titanium is an interesting element because its oxide is a semi-conductor with a high band gap. However, doping with relevant elements through bioincorporation is challenging, and it is necessary to understand the biology involved in element uptake and incorporation. Here we present data on bioincorporation of Ti into the silica frustules of the pennate diatomPinnulariasp. (Ehrenberg) and show that the distribution of the incorporated Ti is inhomogeneous both between and within valves. More than a tenfold increase of Ti in newly synthesised valves was achieved, and increased Ti around the pores was confirmed by both EDS and EELS analyses. HAADF STEM spectroscopy revealed a grainy surface with amorphous silica particles of 4 to 5 nm in size. These observations are explained by what is known from the physico-chemical processes involved in biosilification and frustule formation, looking into it from a biological point of view.
authors: Department of Biotechnology, Norwegian University of Science and Technology (NTNU), SemSelands veg 6/8, 7491 Trondheim, Norway.
authors: Matilde Skogen
authors: MS
authors: Chauton
authors: Department of Biotechnology, Norwegian University of Science and Technology (NTNU), SemSelands veg 6/8, 7491 Trondheim, Norway.
authors: Lotte M B
authors: LM
authors: Skolem
authors: Department of Biotechnology, Norwegian University of Science and Technology (NTNU), SemSelands veg 6/8, 7491 Trondheim, Norway.
authors: Lasse Mork
authors: LM
authors: Olsen
authors: SINTEF Materials and Chemistry, Postboks 4760 Sluppen, 7465 Trondheim, Norway.
authors: Per Erik
authors: PE
authors: Vullum
authors: SINTEF Materials and Chemistry, Postboks 4760 Sluppen, 7465 Trondheim, Norway.
authors: John
authors: J
authors: Walmsley
authors: Department of Biotechnology, Norwegian University of Science and Technology (NTNU), SemSelands veg 6/8, 7491 Trondheim, Norway.
authors: Olav
authors: O
authors: Vadstein
keywords: Bioincorporation; Diatom; Frustulem; Nanostrucuture; Silica; Titanium