Washington: Ballpoint pens filled with high-tech bio-inks can be used to draw sensors directly on the skin to help detect glucose levels in diabetics, scientists say. The research is opening the door to an era when anyone will be able to build sensors, anywhere, according to researchers at the University of California, San Diego. The team has developed high-tech bio-inks that react with several chemicals, including glucose.
They filled off-the-shelf ballpoint pens with the inks and were able to draw sensors to measure glucose directly on the skin and sensors to measure pollution on leaves. Researchers envision sensors drawn directly on smartphones for personalised and inexpensive health monitoring or on external building walls for monitoring of toxic gas pollutants. The sensors also could be used on the battlefield to detect explosives and nerve agents.
“Our new biocatalytic pen technology, based on novel enzymatic inks, holds considerable promise for a broad range of applications on site and in the field,” said Joseph Wang, the chairman of the Department of NanoEngineering. The team used pens, loaded with an ink that reacts to glucose, to draw reusable glucose-measuring sensors on a pattern printed on a transparent, flexible material which includes an electrode.
Researchers then pricked a subject’s finger and put the blood sample on the sensor. The enzymatic ink reacted with glucose and the electrode recorded the measurement, which was transmitted to a glucose-measuring device. Researchers then wiped the pattern clean and drew on it again to take another measurement after the subject had eaten.
Researchers estimate that one pen contains enough ink to draw the equivalent of 500 high-fidelity glucose sensor strips. Nanoengineers also demonstrated that the sensors could be drawn directly on the skin and that they could communicate with a Bluetooth-enabled electronic device that controls electrodes called a potentiostat, to gather data. The pens would also allow users to draw sensors that detect pollutants and potentially harmful chemicals sensors on the spot.
Researchers demonstrated that this was possible by drawing a sensor on a leaf with an ink loaded with enzymes that react with phenol, an industrial chemical, which can also be found in cosmetics, including sunscreen. The leaf was then dipped in a solution of water and phenol and the sensor was connected to a pollution detector. The sensors could be modified to react with many pollutants, including heavy metals or pesticides.The findings were published in the journal Advanced Healthcare Materials.