Histological, spectroscopic, and surface analysis of microdamage in bone: Toward real-time analysis using fluorescent sensors

This paper describes the characterization of microdamage in bones histologically, spectroscopically, and by surface analysis. A set of fluorescent (photoinduced electron transfer, PET) sensors, bearing phenyliminodiacetate moieties as ion receptors, was used to investigate the selective labeling of microdamage in bones, which can have significant value for analysis of bone structures in humans. Scratched and unscratched surfaces of the bone were studied using fluorescence microscopy, Raman spectroscopy, SEM, and EDXA. These results were compared to those using Rose Bengal dye. The overall results show that selective labeling of scratches occurred for all the fluorescent sensors, which can be attributed to the interaction of dyes via binding at free lattice sites (via the receptors), through ionic interactions with free lattice sites or by incorporation in the broken lattices. The principal mode of operation is most likely due to the binding of these sensors to Ca(II) at microdamage sites.