New Covid Test using Pencil Lead

Researchers from University of Pennsylvania in US have developed a new cheaper, faster and more accurate Covid diagnostic test that uses electrodes made from graphite to test the SARS CoV-2 Virus. It is the material found in pencil lead.


  • Researchers noted that, current tests were limited by the trade-off between accuracy and the time it takes for the analysis of sample.
  • They highlighted that, use of Graphite electrodes reduce the cost of testing to $1.50 per test.

About Graphite

Graphite is a crystalline form of element carbon. In Graphite, atoms of carbon are arranged in a hexagonal structure. Graphite is also called as plumbago. It occurs naturally in this form only and is considered as the most stable form of carbon under standard conditions.

Features of Graphite

  • Graphite is converted to diamond under high pressures and temperatures.
  • It is used in pencils and lubricants.
  • It is a good conductor of heat and electricity.
  • Its high conductivity makes it suitable for electronic products like electrodes, batteries and solar panels.

Types of Graphite

Major types of natural graphite are:

  1. Crystalline small flakes of graphite– It occurs naturally as an isolated, flat, plate-like particle with hexagonal edges (if unbroken) and irregular or angular edges (when not broken).
  2. Amorphous graphite– Fine flake graphite is called as amorphous graphite.
  3. Lump graphite– Also called as vein graphite. It occurs in fissure veins or fractures.

Occurrence of Graphite

Graphite occurs in metamorphic rocks because of reduction of sedimentary carbon compounds during metamorphism. It also occurs in igneous rock. Minerals associated with graphite are calcite, quartz, micas and tourmaline.


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