A simple sensor for liver cancer

Researchers from the Indian Institute of Science (IISC) have developed a unique luminescent probe that uses Terbio, a rare earth metal, to feel the presence of an enzyme called β-glucuronidase, which can help in the detection of liver cancer.

The work is published in it Chemistry: An Asian magazine.

Β-glucuronidase is an evolutionarily preserved enzyme that is found in all life forms, from microbes to plants and animals. Its central function is to decompose a sugar acid called glucuronic acid. Beyond its biological omnipresence, enzyme also functions as a critical biomarker for liver cancer. In fact, an increase in β-glucuronidase often accompanies the cancers of colon, breast and renal, as well as urinary tract infections and AIDS.

“Conventional colorimetry and fluorescence methods to detect such enzymes are often restricted by the sensitivity or interference of the background signals. The capacity of rare earth metals to have long -life excited states allows us to filter short -term background fluorescence, which results in a much clearer signal,” says Ananya Biswas, old PH.D. IISC student and co-for The author of The Paper.

The roots of the project date back to almost a decade, starting with the experiments of the equipment on metal ions and its gel formation properties. The team discovered that Terbio ions were expressed in a gel matrix derived from bile salts can emit green fluorescence.

Within the same gel matrix, the team added an organic molecule called 2,3-Dhn (2,3-dihydroxinafthalene) “masked” with glucuronic acid. When this modified molecule shorts, 2.3-Dhn is released. The researchers then shone with UV light in the sample.

“Free 2,3-Dhn acts as a ‘antenna’, which absorbs UV light and energy transfer to nearby terbian ions, greatly improving its green emission,” explains Uday Maitra, an honorary professor in the Department of Organic Chemistry, Iisc, and the corresponding author of the study.

“The gel matrix … ensures sufficient proximity between the ‘antenna’ and terbio ions, facilitating efficient energy transfer.”

To facilitate the application, the team designed this test as a simple paper -based sensor when anchoring the gel matrix on a paper disc. When β-glucuronidase is added previously treated with 2.3-DHN modified, the album exhibits a much stronger green glow under UV light.

The only thing about this technique is the analysis. Unlike conventional high -end fluorescence detection systems, these sensors can be analyzed using a UV and Imagej lamp, openly open and accessible source software, which makes this technique ideal for limited resources configurations.

Using this protocol, the detection limit (LOD), the lowest enzyme concentration that can be detected reliably, is 185 ng/ml. To put this in perspective, the levels of β-glucuronidase of around 1,000 ng/ml are typically associated with the beginning of decompensated cirrhosis, an advanced stage of liver disease.

With liver cancer claiming more lives every year, this technological advance is timely and promising. Given the broad clinical relevance of β-glucuronidase such as biomarker in different types of cancers, neonatal jaundice and Aine induced toxicity, this sensor offers a potentially powerful detection tool.

The authors say that clinical studies must still be carried out to validate the trial. But they hope that such sensors can reduce the cost of detecting clinically significant biomarkers.