Analysis of cross-sections of ditylum brightwelli biosilica by tapping mode atomic force microscopy and scanning electron microscopy
Por:
Heredia A., Silva S., Santos C., Delgadillo I., Vrieling E.G.
Publicada:
1 ene 2008
Resumen:
The nanostructure of cross sections of amorphous biosilica from the marine diatom Ditylum brightwellii was characterized by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The phase images obtained by tapping mode (TM) AFM enabled high resolution distinction between solid biosilica and encapsulated matter of a different chemical nature. The analysis of cross-sections further revealed that nanostructural organizations of the silica depended on the regions that were examined. For D. brightwellii biosilica distinct types of organization were found in for the areas close to the central setae of the valve and the valve wall. For the prior, silica spheres of about 20 nm in diameter contained in so-called brick-mortar structure, which resemble those of other biominerals. In addition, nanochannels and pores were detected, which were fully embedded within the silica and based on phase behavior occasionally contained matter other than silica. In contrast to SEM, TM-AFM indicated that the valve wall appeared to be more compact and that it was probably comprised of two silica layers not related to the overlay from gridle bands. In conclusion, TM-AFM proved to be a sensitive tool for the high resolution qualitative analysis of phase behavior differences in solid biosilicas, especially when encapsulated matter such as organic compounds has not been extracted. © 2008 American Scientific Publishers.
Filiaciones:
Heredia A.:
Instituto tie Ciencias Nucleares, Universidad National Autónoma tie México, Circuito Exterior, C.U. 04510, México D.F., Mexico
Department of Ceramics and Glass Engineering, Center for Research in Ceramics and Composite Materials, University of Aveiro, 3810-193 Aveiro, Portugal
Silva S.:
Centro de Estudos do Ambiente e do Mar, Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal
Santos C.:
Centro de Estudos do Ambiente e do Mar, Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal
Delgadillo I.:
Department of Chemistry, Campus Universitário de Santiago, University of Aveiro, 3810-193 Aveiro, Portugal
Vrieling E.G.:
Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, P.O. Box 14, 9750 AA Haren, Netherlands
|