New IISc research offers to detect glucose through painless photoacoustics

Glucose rotates the polarised light and the rotation increases with concentration, which is reflected in the acoustic signal intensity. Therefore, measuring the strength of the acoustic signal allowed the researchers to work backwards and estimate the concentration of glucose.

A new study by researchers at the Indian Institute of Science (IISc.) has offered an alternative to pricking a needle into the skin to detect blood glucose level in people suffering from diabetes.

According to IISc, “Blood glucose is usually measured using invasive methods involving pricking a small needle in the skin. But people suffering from diabetes have to test their glucose levels many times in a day. This repeated use of needles is inconvenient, and can increase the risk of potential infections.”

Researchers in the Department of Instrumentation and Applied Physics (IAP) have offered an alternative solution via a technique called photoacoustic sensing.

In this technique, when a laser beam is shone on biological tissue, the tissue components absorb the light and the tissue heats up slightly (less than 1°C).

This causes the tissue to expand and contract, creating vibrations, which can be picked up as ultrasonic sound waves by sensitive detectors.

Different materials and molecules inside the tissue absorb different amounts of the incident light at different wavelengths, creating individual ‘fingerprints’ in the emitted sound waves.

Importantly, this procedure does not damage the tissue sample being studied.