Guwahati (Assam) | Researchers from the Indian Institute of Technology Guwahati led by Professor Dipankar Bandyopadhyay, Department of Chemical Engineering, has developed a reliable and affordable Glycemic Index (GI) sensor, suitable for point-of-care detection.

This sensor can determine the GI of different food sources in real-time which is crucial for diabetes management. The Glycemic Index or GI is a measure that ranks carbohydrate-containing foods based on how they affect blood sugar levels when consumed.

High-GI food can cause a rapid spike in blood glucose levels, followed by a swift decline. Moreover, these high-GI foods stimulate an increased demand for insulin, contributing to the risk of developing type-2 diabetes. Importantly, low-GI food helps to prevent diabetes, heart disease, obesity, and cancer.

As the trend of fast-food increases among the world's working population, the need for a portable device that can immediately detect and guide the user about the GI of the food arises.

The point-of-care-testing (POCT) prototype developed by the IIT Guwahati team can detect the glycemic Index of common food sources in approximately 5 minutes. Explaining the detection methods Prof. Bandyopadhyay said, "We developed a composite nanoenzyme by combining gold nanoparticles with alpha-amylase to break down long-chain

starch molecules into simpler sugars. We found that this nanoenzyme of approx 30 nanometer size has remarkable heterogeneous catalytic properties to rapidly degrade starch into maltose at room temperature."

The amount of maltose produced is then electrochemically detected to classify the food sources into Rapidly Digestible Starch (RDS) and Slowly Digestible Starch (SDS) along with Resistant Starch (RS).

Explaining the real time monitoring on fast food, Professor Bandyopadhay said, "When we tested the device on fast foods like crackers, biscuits, chips, and bread, we found that crackers have the most RDS, followed by potato chips, and then brown bread. Notably, the SDS/RS of brown bread releases maltose slowly, causing a gradual increase in

glucose levels and a lower response from insulin in the body."