Wireless ‘Tooth Tattoo’ Biosensor Detects Harmful Bacteria

Using silk strands pulled from cocoons and gold wires thinner than a spider’s web, researchers at Princeton University have created a removable tattoo that adheres to dental enamel and could eventually monitor a patient’s health with unprecedented sensitivity.

In a laboratory in Princeton’s Engineering Quadrangle, a graduate student demonstrated the system’s wireless capability, breathing across a sensor attached to a cow’s tooth. Instantaneously, the sensor generated a response to the student’s breath and transmitted a signal to a nearby monitor.

The researchers created the tattoo by bundling the silk and gold with graphene — an extremely thin sheet of carbon in which atoms are arranged in a honeycomb lattice. The material’s unique properties allowed the researchers to construct a small, flexible device able to detect bacteria at a much higher sensitivity level than traditional methods. In tests, the researchers detected samples of bacteria that can cause surgical infections and others that can lead to stomach ulcers.

“In principle, the graphene can be tailored to detect a range of different things,” said McAlpine, an assistant professor of mechanical and aerospace engineering at Princeton. “It can be configured to detect DNA or certain viruses. Here, we detect a single bacterium.”

The full Princeton article can be found here.