Researchers have designed a tiny sensor using a circular DNA (plasmid) found in bacteria and other lowly life forms1. The metal conjugated DNA can be utilized as sensor for mercury contamination.
The toxic effects of mercury depend on its chemical form and the route of exposure. Methylmercury (CH3Hg) is the most toxic form. It affects the immune system, alters genetic and enzyme systems, and damages the nervous system. Small environmental concentrations of methylmercury can readily accumulate to potentially harmful concentrations in fish, fish-eating wildlife and people.
To develop the sensor, researchers took plasmid DNA and exposed it to mercury nanoparticles. The mercury nanoparticles got embedded inside the DNA scaffold due to the strong and exclusive interaction of the nanoparticles with nitrogen of the nucleic acid bases.
The interaction of the mercury nanoparticles with the guanine-cytosine base pair led to the formation of two mercury metal-base complexes. This may find application as the sign of ion-DNA interactions.
The authors of this work are from: Institute of Physics, Bhubaneswar, and Department of Biotechnology, Utkal University, Bhubaneswar, India.
