  Bovine serum albumin (BSA) Langmuir monolayer, as a model of
biomineralization-associated proteins, was used to study its effect on
regulated biomineralization of calcium carbonate. The effects of the BSA
Langmuir monolayer and the concentration of the subphase solution on the
nucleation and growth processes and morphology of the calcium carbonate crystal
were investigated. The morphology and polymorphic phase of the resulting
calcium carbonate crystals were characterized by scanning electron microscopy
(SEM) and X-ray diffraction analysis (XRD). Moreover, the interaction
mechanisms of the subphase solution with the BSA Langmuir monolayer were
discussed. It was found that BSA Langmuir monolayer could be used as a template
to successfully manipulate the polymorphic phase and crystal morphology of
calcium carbonate and had obvious influence on the oriented crystallization and
growth. The final morphology or aggregation mode of the calcite crystal was
closely dependent on the concentration of calcium bicarbonate solution. It is
expected that this research would help to better understand the mechanism of
biomineralization by revealing the interactions between protein matrices and
crystallization of calcium carbonate crystal.
