Nanoscale chemical tomography of buried organic–inorganic interfaces in the chiton tooth

Nanoscale tomography of complex biomaterials Many biomineralized tissues, such as teeth and bone, are hybrid inorganic–organic materials whose properties are determined by their convoluted internal structures. Lyle Gordon and Derk Joester now show how the internal structural and chemical complexity of such biomaterials and their synthetic analogues can be elucidated using pulsed-laser atom-probe tomography (APT), an established technique in metallurgical and semiconductor research. The model for the study was a tooth from a marine mollusc, the Eastern beaded chiton. The resulting high-resolution three-dimensional chemical maps reveal individual organic fibres within the tooth that have different compositions, and therefore probably different functional roles in controlling the interactions between the organic matrix and inorganic mineral phases. As well as revealing the nature of naturally occurring materials, the use of APT in this field should provide useful data for the design of bio-inspired composites for medical and industrial applications.