Researchers at the Indian Institute of Science (IISc) have developed an innovative glowing paper sensor that could enable early detection of liver cancer. Powered by a rare earth metal called terbium, the sensor emits a bright green glow under ultraviolet (UV) light, offering a cost-effective, highly sensitive diagnostic alternative.
Detecting Cancer-Linked Enzyme with Terbium’s Glow
As reported by TOI, the sensor works by identifying the enzyme β-glucuronidase, which occurs naturally in the body but is found in elevated levels in patients with liver cancer. Other health conditions, including colon, breast, and kidney cancers, infections, and AIDS, also involve this enzyme.
“Traditional methods often struggle with background interference or lack of sensitivity,” explained Ananya Biswas, co-author of the study and a former PhD student at IISc. “Terbium, however, glows for longer durations, helping us cut through the noise for clearer detection.”
Decade-Long Research Leads to Breakthrough
The project began nearly ten years ago when the team at IISc started exploring metal ions and their gel-forming properties. They discovered that terbium, when mixed with bile salt gels, produces a strong green luminescence under UV light.
To build the sensor, researchers added an organic molecule called 2,3-DHN, which was coated with glucuronic acid. This coating kept the sensor inactive. However, when β-glucuronidase was present in a sample, it removed the coating, releasing the active molecule. The molecule then absorbed UV energy and transferred it to nearby terbium ions, amplifying the green glow.
Turning Gel into a Paper-Based Diagnostic Tool
The researchers transferred this glowing gel onto small paper discs, creating an easy-to-use sensor. When exposed to samples containing β-glucuronidase, the disc glows increasingly bright under UV light, indicating the enzyme’s presence.
Importantly, the sensor requires only a simple UV lamp and free software like ImageJ to analyze the glow. This accessibility makes it ideal for low-resource settings, especially where costly lab infrastructure is unavailable.
Highly Sensitive and Affordable
The sensor detects enzyme levels as low as 185 nanograms per millilitre, which is significantly below the typical range observed in severe liver disease. This makes the technology not only accurate but also potentially life-saving by catching liver cancer at an earlier stage.
Potential for Broader Medical Applications
Researchers remain optimistic, though they still need to conduct clinical trials. They believe the sensor could be used to detect not just liver cancer but also conditions such as jaundice, drug-induced toxicity, and other diseases linked to abnormal β-glucuronidase levels.
IISc’s team blends deep scientific research with simple, scalable technology. This approach could transform how doctors detect liver cancer and other diseases, especially in underserved regions.