title: In situ raman spectral mapping study on the microscale fibers in blue coral (Heliopora coerulea) skeletons.
abstract: The presence and localization of organic matrix associated with the aragonite phase in the fibers of blue coral Heliopora coerulea skeletons were studied by in situ microRaman mapping spectra, with a spatial resolution of ~0.3 μm. Spatial variations in the amounts and chemical compositions of the fibers were imaged. The results showed that the amide I and the α-helix of amide III were perpendicular to the c-axis of fibers' growth, whereas the β-turns/sheet of amide III was in the parallel conformation. Visible S-S and C-S bonds were consistent with the XANES results, which indicated the existence of organic sulfur in coral skeletons. Regular cyclic changes between aragonite and organic matrix refined a stepping growth mode of the fibers' biomineralization. An inorganic PO(4) bond was detected and exhibited the same concentration variation trends as the v(4) aragonite bands. Instead of providing an ocean P proxy on the subseasonal to centennial scale by LA-ICPMS, the possibility was raised of producing high resolution surface ocean phosphorus records on daily environmental variation via P/Ca variation cycles determined from Raman mapping data.
authors: State Key Laboratory of Estuarine and Coastal Research, East China Normal University, 3663 North Zhongshan Road, 200062 Shanghai, PR China. ffzhang@sklec.ecnu.edu.cn
authors: Fenfen
authors: F
authors: Zhang
authors: Weiying
authors: W
authors: Cai
authors: Jichun
authors: J
authors: Zhu
authors: Zhenrong
authors: Z
authors: Sun
authors: Jing
authors: J
authors: Zhang
mesh_terms: D000818:Animals; D037421:Anthozoa; D002119:Calcium Carbonate / Q000737:chemistry*; D017433:Protein Structure, Secondary; D012863:Skeleton; D013059:Spectrum Analysis, Raman; D056928:X-Ray Absorption Spectroscopy
chemical_list: D002119:Calcium Carbonate