Structural Development of Mercaptophenol Self-Assembled Monolayers and the Overlying Mineral Phase during Templated CaCO3 Crystallization from a Transient Amorphous Film

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• 作者：Jonathan R. I. Lee ; T. Yong-Jin Han ; Trevor M. Willey ; Dongbo Wang ; Robert W. Meulenberg ; Joakim Nilsson ; Patricia M. Dove ; Louis J. Terminello ; Tony van Buuren ; James J. De Yoreo
• 刊名：Journal of the American Chemical Society
• 出版年：2007
• 出版时间：August 29, 2007
• 年：2007
• 卷：129
• 期：34
• 页码：10370 - 10381
• 全文大小：534K
• 年卷期：v.129,no.34(August 29, 2007)
• ISSN：1520-5126

文摘

Formation of biomineral structures is increasingly attributed to directed growth of a mineral phasefrom an amorphous precursor on an organic matrix. While many in vitro studies have used calcite formationon organothiol self-assembled monolayers (SAMs) as a model system to investigate this process, theyhave generally focused on the stability of amorphous calcium carbonate (ACC) or maximizing control overthe order of the final mineral phase. Little is known about the early stages of mineral formation, particularlythe structural evolution of the SAM and mineral. Here we use near-edge X-ray absorption spectroscopy(NEXAFS), photoemission spectroscopy (PES), X-ray diffraction (XRD), and scanning electron microscopy(SEM) to address this gap in knowledge by examining the changes in order and bonding of mercaptophenol(MP) SAMs on Au(111) during the initial stages of mineral formation as well as the mechanism of ACC tocalcite transformation during template-directed crystallization. We demonstrate that formation of ACC onthe MP SAMs brings about a profound change in the morphology of the monolayers: although the as-prepared MP SAMs are composed of monomers with well-defined orientations, precipitation of theamorphous mineral phase results in substantial structural disorder within the monolayers. Significantly, apreferential face of nucleation is observed for crystallization of calcite from ACC on the SAM surfacesdespite this static disorder.