Ah, chitin … the cheap and plentiful substance, which occurs naturally in crustacean shells, has already been suggested for use in things like wound dressings, cheaper pharmaceuticals, and even proton-conducting transistors. Now, researchers from the National Taiwan Ocean University have found that when combined with silver, it could also be used to kill malaria-spreading mosquitoes.
More specifically, the mixture has been proven effective at killing mosquito larvae, while they're still in the water.
Led by Prof. Jiang-Shiou Hwang, the research team started by oven-drying and then crushing the shells of hydrothermal vent crabs, and then extracting chitin and other minerals from them. These were subsequently mixed with silver nitrate, resulting in a solution of chitin-enriched silver nanoparticles.
That solution was later sprayed over six water reservoirs at India's National Institute of Communicable Disease Centre. It was found that even in low concentrations, the nanoparticles killed mosquito larvae and pupa very effectively.
Hwang believes that this is due to the particles passing through the insects' outer cuticle and into individual cells. There, they "interfere with various physiological processes that are part of a mosquito's life cycle."
As a side benefit, the solution was also found to inhibit the growth of dangerous bacteria such as Bacillus subtilis, Escherichia coli, Klebsiella pneumoniae and Proteus vulgaris. When tested on goldfish, however – which feed on mosquito larvae – it was found to have no harmful effect.
A paper on the research was recently published in the journal Hydrobiologia.