Periodic Nucleation of Calcium Phosphate in a Stirred Biocatalytic Reaction

Highly ordered superstructures composed of inorganic nanoparticles appear in natural and synthetic systems, however the mechanisms of non-equilibrium self-organization that may be involved are still poorly understood. Herein, we performed a kinetic investigation of the precipitation of calcium phosp...

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Bibliographic Details
Main Authors: Bohner Bíborka
Bánsági Tamás
Tóth Ágota
Horváth Dezső
Taylor Annette F.
Format: Article
Published: 2020
Series:ANGEWANDTE CHEMIE-INTERNATIONAL EDITION 59 No. 7
doi:10.1002/anie.201911213

mtmt:31131403
Online Access:http://publicatio.bibl.u-szeged.hu/18594
Description
Summary:Highly ordered superstructures composed of inorganic nanoparticles appear in natural and synthetic systems, however the mechanisms of non-equilibrium self-organization that may be involved are still poorly understood. Herein, we performed a kinetic investigation of the precipitation of calcium phosphate using a process widely found in microorganisms: the hydrolysis of urea by enzyme urease. With high initial ratio of calcium ion to phosphate, periodic precipitation was obtained accompanied by pH oscillations in a well-stirred, closed reactor. We propose that an internal pH-regulated change in the concentration of phosphate ion is the driving force for periodicity. A simple model involving the biocatalytic reaction network coupled with burst nucleation of nanoparticles above a critical supersaturation reproduced key features of the experiments. These findings may provide insight to the self-organization of nanoparticles in biomineralization and improve design strategies of biomaterials for medical applications.
Physical Description:2823-2828
ISSN:1433-7851