Princeton scientists develop tooth tattoos that can detect and identify bacteria

Many expert and artistic dental technicians are capable of layering amazing images into crowns to create the cosmetic marvels known as tooth tattoos. But while those designs are purely to satisfy patients with unique esthetic sensabilities, a team of Princeton-based researchers are developing a way for special designs layered onto teeth to not just detect the presence of specific bacterial infections, but to identify the bacteria and wirelessly transmit the information to a remote sensor.

Michael McAlpine and his team at Princeton published a paper in the current issue of the journal Nature Communications where they describe the graphene-based sensors designed to be applied to the teeth for rapid disease detection. The nanoscale graphene material was applied to the tooth after being printed on a water soluble silk material that is washed away after the sensor is affixed. While the current generation of these sensors are being affixed to teeth, the concept of graphene-based biosensors could eventually be used to affix disease detectors in other places.

In the current generation of this technology, the sensors work when biofunctional peptides featuring naturally occurring antimicrobial proteins are attached to the graphene base. The proteins interact with specific bacterial strains to create a small electric field that modulates the graphene's conductivity. When probed with the external sensor, the graphene's conductivity changes can be detected and used to determine the bacterial concentrations.

This technology may be a long way from commercial application, but it's easy to imagine potential uses for such sensors. Hospitals might affix sensors to patients' teeth when they're admitted so new infections can be automatically detected, or soldiers wounded in battle could receive sensors to alert medical personnel in case their injuries worsen due to infection. Whether this technology remains on teeth or ends up being affixed to different tissues is unclear, but for now teeth get to be the first biological tissue to be directly interfacing with graphene bacteria sensors.