Quantum sensing of chiton teeth

Quantum-based magnetic microscopy shows that iron nanoparticles are magnetised in the same direction in the early stages of teeth development in chitons (a marine mollusc).

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Chitons are a marine mollusc that use their teeth to scrape food from rocky surfaces. Their teeth are the hardest known in the animal kingdom. They contain an iron oxide called magnetite, which contributes to their strength.

A research team led by Dr David Simpson, from the School of Physics at the University of Melbourne, investigated how magnetism influences the incorporation of magnetite during chiton tooth development. To do this, they tailored their existing quantum-based magnetic microscope technology.

Magnetism is known to play a role in how biominerals are used to strengthen hard structures like bones and teeth during organism development. But traditional microscopes cannot capture the detail needed to show how the process works.

Chitons' tooth development can be tracked from beginning to end. They use a tongue-like organ that has rows of teeth (the researchers studied a species with 87 rows). The teeth develop in stages – the back rows are unmineralised (they don’t contain iron), while the front rows are fully mineralised (containing iron).

Using their quantum-based microscope, the researchers found that at the onset of mineralisation, magnetite nanoparticles are magnetised in the same direction throughout the tooth, even though the nanoparticles themselves are not arranged in an ordered way.

The researchers propose that the magnetic field from the magnetite nanoparticles may play a role in the self-assembly of the parallel rods of magnetite found in fully mineralised chiton teeth.

Next steps

The team is making its quantum-based magnetic microscopy technique available to researchers in physical and biological sciences who study iron minerals.


ARC Australian Laureate Fellowship to Professor Lloyd Hollenberg

New Views Of Life: Quantum Imaging In Biology (FL130100119)

ARC Discovery Early Career Researcher Award to Dr Jean-Philippe Tetienne

Graphene Meets Diamond: 2d Spintronics Probed With Diamond Quantum Sensors (DE170100129)


McCoey JM et al (2020) Quantum magnetic imaging of iron biomineralization in teeth of the chiton Acanthopleura hirtosa. Small Methods 4: 1900754. doi: 10.1002/smtd.201900754

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Banner image: Bright-field microscopy shows the stages of iron mineralisation in chiton teeth, with the darker teeth fully mineralised and the lighter teeth not yet mineralised. Image: Jeremy Shaw, University of Western Australia

First published on 14 March 2022.

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