Most of us remember mood rings, right? Purple meant happy, and black meant stressed and every color in between was every mood in between. Some, even physiologists, believe there is some accuracy to this, corresponding to the temperature of one’s body depending on their mood, but what if there was an accessory that gave even more valuable biodata?

New research from Tufts University shows that tattoos could measure blood oxygen levels and other important biological markers. 

Invaluable ink

Fibroin, a new sensor in the form of a gel made from the protein components of silk, works very well as an injectable to read its host’s oxygen levels. It’s unlikely to invoke an immune response and can last under the skin from a few weeks to up to a year. 

“Silk provides a remarkable confluence of many great properties,” says David Kaplan, professor of engineering in the School of Engineering at Tufts University and lead investigator of the study. “We can form it into films, sponges, gels, and more. Not only is it biocompatible, but it can hold additives without changing their chemistry, and these additives can have sensing capabilities that detect molecules in their environment. The oxygen sensor is a proof of concept for a range of sensors we could create.”

The silk proteins’ chemistry allows them to turn into an oxygen sensor with an additive called PdBMAP, which glows, or phosphoresces, when exposed to intense light. Researchers are still exploring ways to lengthen the longevity of this additive, but right now it shows an easy and at-hand method of detecting a patient’s oxygen levels. It was effective in animal models and is very important in an age when patients, perhaps with COVID-19, need their oxygen closely monitored. 

Prescribed tattoos?

Researchers believe that since this new fibroin sensor can be responsive to blood oxygen levels, why not other important blood components? Glucose, for instance, is something that diabetics need to measure on a daily basis, often by drawing their blood. How much easier would things be for patients and medical professionals if all diabetics needed to do to measure their blood sugar was shine a light over a wrist tattoo of a rose or dandelion?

“We can envision many scenarios in which a tattoo-like sensor under the skin can be useful,” says Thomas Falcucci, a graduate student in Kaplan’s lab who developed the tattoo sensor. “That’s usually in situations where someone with a chronic condition needs to be monitored over a long period of time outside of a traditional clinical setting. We could potentially track multiple blood components using a sensor array under the skin.”

Source Study: Tufts Now — Scientists Create Tattoo-like Sensors That Reveal Blood Oxygen Levels | Tufts Now