Tattooing Teeth With Graphene Could Warn of Bacteria and Dental Decay

Graphene Tooth Telemetry System

McAlpine et al./Nature Communications

Electronic tattoos promise to help people monitor health in all kinds of ways, from heart rates to blood sugar and more. Now here's one that can monitor your tooth-brushing skills. A tooth-based sensor can detect different types bacteria in your saliva that can cause a variety of health problems.

The sensor is made of graphene and can detect bacteria in our mouths to the single-cell level, according to researchers at Princeton and Tufts universities. Michael McAlpine and colleagues developed a method to print graphene nanosensors onto a silk substrate. They added electrodes and an inductive coil to power the device, which can then be transferred onto teeth or other biological materials.

The graphene is then doped with naturally occurring antimicrobial peptides, which bind to bacteria and can be used as a bug detection system. The result is a battery-free, wireless sensing device that can pinpoint exactly which type of bacteria is present in a person's mouth. Because it's imprinted onto silk, the detector has elastic properties, so it could also be integrated onto soft tissues, too, not just tooth enamel. To test it, McAlpine and colleagues grafted it onto a raw chicken breast.

The sensor could also be used in hospitals or facilities where antibiotic-resistant bacteria can proliferate, the researchers say. They attached the graphene sensor to an IV bag and then poured some bacteria-containing solution on it. The sensor was able to detect low levels of Staph. aureus, the bane of many hospitals' existence.

It's not clear how long this type of detector would work in a person's mouth — presumably, if you brush your teeth like you're supposed to, it would easily rub off. But it's another step toward omnipresent passive medical sensors, keeping constant tabs on our health from within.

The research was published last week in Nature Communications.