Research Highlight

Antibiotic dots

doi:10.1038/nindia.2009.339 Published online 24 November 2009

Researchers have designed quantum dots (QDs), extremely tiny crystals which when bound to negatively charged ions show antibacterial activity against Escherichia coli1.

This opens up a new avenue in combating bacterial infections.

Quantum dots are a class of semiconducting nanocrystals containing microscopic amounts of the semiconductor material. The researchers made quantum dots with surface adsorbed anionic species of acetate ions and nitrate ions using zinc oxide (ZnO).

The particle size was found to be 3-5 nm for acetate adsorbed ZnO QDs and 4-7 nm for nitrate adsorbed ZnO QDs. Both showed antibacterial activity though acetate adsorbed QDs were better. This could be attributed to the inherent ability of acetate ions to generate reactive oxygen species.

The acetate adsorbed QDs have potential application for its bactericidal effects.


  1. Joshi, P. et al. Role of surface adsorbed anionic species in antibacterial activity of ZnO quantum dots against Escherichia coli. J. Nanosci. Nanotechnol. 9, 6427-6433 (2009) | Article | PubMed |