Kevin Plaxco, PhD, received an email with the subject line, “Rats 3, postdoc 0.”

Because some days the rats win.

Plaxco has spent two decades trying to build a biosensor that works for longer than a day in the human body, measuring any molecule in real time. Preliminary results and shorter runs — including an in vivo success in 2017 — suggested that he was getting close.

Finally, after several iterations, a three-dimensional printed housing worked. The biosensors lasted for 7 days, accurately monitoring levels of the antibiotic tobramycin.

“We showed we could push the measurement duration to a week, making a measurement every 12 seconds,” Plaxco said. “Working for longer than a day is a major breakthrough, because a device that needs to be replaced every few days is way better than one that needs to be replaced several times a day.”

Read more about Kevin Plaxco's research in Medscape.