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A team of researchers led by Dr. Michael McAlpine of Princeton University have developed a gold- and carbon-based biosensor that can be affixed to a tooth . The purpose of the sensor, which is made up primarily of a very strong form of carbon called graphene, is to detect sequences of DNA that are specific to pathogenic bacteria.
Because of the sensor’s ability to detect bacteria in very small quantities, the researchers hope it will be of diagnostic utility in the case of infection. Explains Dr. McAlpine:
This is a real-time, wireless response from a sensor that can be directly interfaced with a variety of biomaterials. In principle, the graphene can be tailored to detect a range of different things. It can be configured to detect DNA [of bacteria] or certain viruses.
Currently, the sensor is a bit too large to fit on a human tooth; the initial research was conducted on cow teeth. However, the team is hopeful that further work will reduce the sensor’s size, while maintaining the ability to transmit data wirelessly to a nearby receiver.
A major challenge associated with the project was finding a way to affix the device to a tooth. While silicon is often used as the platform (substrate) for a biosensor, it’s too brittle to be practical in this application. The team ended up using silk, which not only affixes well to the tooth surface, but can also be dissolved by enzymes allowing for removal of the device.
As the researchers work to make the sensor smaller, they’ll also be doing research on the effects of eating food and brushing teeth on the device. The ultimate goal is to create a sensor that can be affixed for a short period of time and removed when no longer needed, but which isn’t damaged by normal activities.
Source: Princeton University News
- Mannoor et al. Graphene-based wireless bacteria detection on tooth enamel. Nat Commun. 2012 Mar 27;3:763. doi: 10.1038/ncomms1767.