Painless glucose check via sound waves

Researchers at the Indian Institute of Science in Bengaluru have cooked up a needle-free way to track blood glucose, swapping pricks for photoacoustic sensing. A laser zaps tissue, heating it just a whisper—less than a degree—triggering vibrations that sensitive detectors catch as sound waves, fingerprinting glucose levels without a scratch.

The trick’s in polarized light—think sunglass vibes—twisting as it hits glucose, a quirky chiral molecule, and tweaking the sound’s intensity. Jaya Prakash, assistant professor at IISc’s instrumentation crew, says they’ve cracked a link between that sound and glucose concentration, testing it spot-on in water, serum, even animal tissue slices. 

It’s not just glucose—naproxen, a painkiller, showed up too, hinting at broader healthcare wins. The team’s pilot tracked a healthy eater’s levels post-meal, though Swathi Padmanabhan, the study’s lead hand, admits the bulky laser’s a hitch—nanosecond pulses aren’t cheap or portable yet. They’re tinkering to shrink it, aiming to slide this into clinics with a quieter buzz.