A simple sensor for liver cancer

Researchers from the Indian Institute of Sciences (IISC) have developed a unique luminescent probe that uses terbium, a metal of rare land, to feel the presence of an enzyme called β-glucuronidase, which can potentially help to detect liver cancer.

The work is published in the Chemistry – An Asian review.

The β -glucuronidase is an enzyme preserved evolvingly found through the forms of life – from microbes to plants and animals. Its central function is to break down a sugar acid called glucuronic acid. Beyond its organic omnipresence, the enzyme is also coupled with critical biomarkers for liver cancer. In fact, an increase in β-glucuronidase often accompanies colon, breast and renal cancers, as well as urinary tract and AIDS infections.

“The conventional methods of colorimetry and fluorescence to detect such enzymes are often limited by the sensitivity or interference of substantive signals. The capacity of rare land metals to have long -term excited states allows us to filter the short -term background fluorescence, resulting in a much more clear signal”, explains Ananya Biswas, Old PH.D. co-prime author of the newspaper.

The project roots go back almost a decade, starting with the team’s experiences on metal ions and their frost formation properties. The team noted that the terbium ions formulated in a gel matrix derived from biliary salts can emit a green fluorescence.

In the same gel matrix, the team added an organic molecule called 2.3-Dhn (2.3-Dihydroxynaphthene) “masked” with glucuronic acid. When β-glucuronidase contrasts this modified molecule, the 2,3-Dhn is released. The researchers then shone the UV light on the sample.

“The free 2.3-DHN acts as an” antenna “- absorbing UV light and transferring energy to nearby terbium ions, considerably improving their green emission,” explains Uday Masitra, honorary professor in the department of organic chemistry, IISC and corresponding author of the study.

“The frost matrix … provides sufficient proximity between the” antenna “and terbium ions, facilitating an effective energy transfer.”

To facilitate the application, the team designed this test as a simple paper sensor by anchoring the gel matrix on a paper disc. When β-glucuronidase pre-cross with modified 2.3-DHN is added, the disc has a much stronger green glow under UV light.

What is unique in this technique is analysis. Unlike the conventional high-end fluorescence detection systems, these sensors can be analyzed using a UV and ImageJ lamp, open-source and freely accessible software, making this technique ideal for resource-limited parameters.

Using this protocol, the detection limit (LOD) – The lowest enzyme concentration which can be reliably detected – has come to 185 ng / ml. To put this in perspective, the levels of β-glucuronidase of around 1,000 ng / ml are generally associated with the start of decompensated cirrhosis, an advanced stage of liver disease.

With liver cancer claiming more lives each year, such a technological advance is both timely and promising. Given the large clinical relevance of β-glucuronidase as a biomarker in different types of cancer, neonatal jurisdiction and toxicity induced by NSAIDs, this sensor offers a potentially powerful screening tool.

The authors say that clinical studies will still have to be carried out to validate the test. But they hope that such sensors will be able to reduce the cost of detecting clinically significant biomarkers.