title: The initial stages of template-controlled CaCO3 formation revealed by cryo-TEM.
abstract: Biogenic calcium carbonate forms the inorganic component of seashells, otoliths, and many marine skeletons, and its formation is directed by an ordered template of macromolecules. Classical nucleation theory considers crystal formation to occur from a critical nucleus formed by the assembly of ions from solution. Using cryotransmission electron microscopy, we found that template-directed calcium carbonate formation starts with the formation of prenucleation clusters. Their aggregation leads to the nucleation of amorphous nanoparticles in solution. These nanoparticles assemble at the template and, after reaching a critical size, develop dynamic crystalline domains, one of which is selectively stabilized by the template. Our findings have implications for template-directed mineral formation in biological as well as in synthetic systems.
authors.affiliation: Laboratory of Materials and Interface Chemistry, Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven, Netherlands.
authors.forename: Emilie M
authors.initials: EM
authors.lastname: Pouget
authors.forename: Paul H H
authors.initials: PH
authors.lastname: Bomans
authors.forename: Jeroen A C M
authors.initials: JA
authors.lastname: Goos
authors.forename: Peter M
authors.initials: PM
authors.lastname: Frederik
authors.forename: Gijsbertus
authors.initials: G
authors.lastname: de With
authors.forename: Nico A J M
authors.initials: NA
authors.lastname: Sommerdijk
mesh_terms: D001639:Bicarbonates / Q000737:chemistry; D002113:Calcification, Physiologic; D002119:Calcium Carbonate / Q000737:chemistry*; D020285:Cryoelectron Microscopy; D003460:Crystallization; D053758:Nanoparticles; D010316:Particle Size; D013229:Stearic Acids
chemical_list: D001639:Bicarbonates; D013229:Stearic Acids; C031183:stearic acid; C031556:calcium bicarbonate; D002119:Calcium Carbonate