An extract made using crushed vegetable waste can convert silver nitrate solution into silver nanoparticles that can inhibit the growth of specific disease-causing bacteria, new research claims1. This offers an eco-friendly way to make silver nanoparticles that are potentially useful for treating bacterial infection.

The synthesis of nanoparticles such as silver nanoparticles requires toxic chemicals. Plant extracts prepared from different plant species have long been in use. However, no previous studies had utilised vegetable waste.

An international team including researchers from Mahendra Arts and Science College in Tamil Nadu, India, prepared an extract of vegetable waste by mixing crushed vegetables, fresh skins of vegetables and damaged leaves with distilled water. Adding this extract to a silver nitrate solution changed the solution from colourless to brown, indicating the formation of silver nanoparticles.

The researchers then added portions of the extract to separate nutrient broths that contained two species of disease-causing bacteria: Klebsiella and Staphylococcus . The extract significantly inhibited the growth of the bacteria, which are known to infect the lungs, urinary tract and skin wounds.

Besides offering a green process for producing antibacterial nanoparticles, this method shows that it is possible to safely utilise market-derived solid waste, shunning the need for waste disposal and thereby reducing the risks of waste-related pollution.