New Bio-Sensor Inks Can Be Filled In Regular Ballpoint Pens – Draw Shapes To Get Diagnosed Or Hunt For Explosives

Regular ballpoint pens may soon replace traditional, and many-a-times, painful techniques to get vital readings off the body. Patients may have to simply draw on their bodies to measure a multitude of parameters.

Ballpoint pens filled with special sensor-laden bio-sensor inks could soon eliminate painful finger pricks for diabetics, and help regular people test their blood glucose levels simply by drawing cartoons – or just a few dots – on their skin. Apart from the medical applications, researchers are evolving the technology to enable these bio-sensor inks to pick-up scents or test for pollutants in the atmosphere simply by drawing on leaves or on buildings’ surfaces.

Astonishingly, the team of engineers from the University of California, San Diego, who developed the ink, managed to fill it in regular, off-the-shelf ballpoint pens. Their ultimate aim is to enable a new type of do-it-yourself sensor with rapid diagnostic capabilities for people with diabetes. However, given the rate at which technology is evolving, especially with bio-sensors, these inks could take a variety of readings apart from sugar levels.

In their current iteration, the bio-sensor ink is made from the enzymes glucose oxidase. The compound not only readily and rapidly reacts to sugar in the blood, but also tyrosinase, which can help detect common pollutants known as phenols. Shockingly, these compounds are quite commonly found in cosmetics and can be toxic at high enough concentrations. Mere compounds aren’t enough to pick-up readings, explained Charles Choi.

“To make these bio-inks serve as electrodes, they added electrically conductive graphite powder. They also added: chitosan, a clotting agent used in bandages, to help the ink stick to surfaces; xylitol, a sugar substitute, to help stabilize the enzymes during chemical reactions; and biocompatible polyethylene glycol, which is used in several drug delivery applications, to help bind all these ingredients together.”

The final product had surprisingly similar consistency of regular inks found in ballpoint pens. Using their pens, researchers were able to draw complete sensors that measured glucose directly onto the wrist of a willing participant. Further technological development would enable the drawing to “talk” with a Bluetooth enabled device for visually offering a detailed read-out of the measurements.

In addition to the measurements of vital signs, the developers are also tweaking the bio-sensor inks to react with many other pollutants, such as heavy metals or pesticides. Though the primary and immediate purpose behind the development is to enable multiple-use testing strips for diabetes monitoring, eventually, these bio-sensor inks would find use in hostile situations as well.

These bio-sensor inks could one day be applied help soldiers search for explosives and chemical weapons merely by applying them on leaves or surfaces and get a reading of the immediate vicinity for presence of explosives or ammunition.

[Image Credit | IEEE Spectrum]