Introduction

• Indian scientists at the Indian Institute of Science (IISc), Bengaluru have developed an innovative paper-based glowing sensor that uses the green fluorescence of terbium, a rare earth metal, to aid in the early detection of liver cancer. This discovery not only marks a breakthrough in biomedical diagnostics but also brings to light the unique properties of terbium, an element with growing importance in the field of advanced electronics and magnetics.

What is Terbium?

• Terbium (Symbol: Tb, Atomic Number: 65) is a rare-earth metal belonging to the lanthanide series of the periodic table. It is a moderately hard, silvery-white metal, known for its green luminescence and unique magnetic properties.

Key Physical and Chemical Properties:

Biomedical Breakthrough: Liver Cancer Sensor

• The IISc-developed sensor utilizes the green glow of terbium to detect biomolecular changes linked with liver cancer. This sensor is low-cost, simple, and paper-based, making it suitable for early-stage diagnostics even in rural or resource-poor settings.

How It Works:

• When specific biomarkers associated with liver cancer are present, terbium ions embedded in the sensor emit a green fluorescence, providing a visual indicator of possible cancer presence.

Applications of Terbium

1. Electronics and Display Technology:

• Terbium compounds are crucial in green phosphors, used in:

• • Fluorescent lamps
  • Cathode-ray tubes (CRTs)
  • LED lighting
  • Computer monitors and TV screens

2. Magnetostrictive Materials:

• Alloys of terbium with dysprosium and iron are used in Terfenol-D, a magnetostrictive material widely used in:

• • Sonar systems
  • Precision actuators
  • Vibration dampers

3. Nuclear Technology:

• Terbium is found in nuclear fission products, contributing to its extraction from nuclear reprocessing waste.

Occurrence and Extraction

• Terbium is not found freely in nature but is derived from rare-earth minerals like:

• Terbium is typically co-extracted along with other rare earths and separated by solvent extraction.

Other Major Rare Earth Elements