Bacterial Growth Response on Interaction with Iron Oxide and Gold Nanoparticles: Measuring Risk to the Environment

Abstract

Nanoparticlemetal oxide and gold represents a new class of important materials that are increasingly being developed for use in research and health related activities. The biological system being extremely critical requires the fundamental understanding on the influence of inorganic nanoparticles on cellular growth and functions. Our study was aimed to find out the effect of Iron oxide (Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> ), Gold (Au) nanoparticles on cellular growth of E. coli. TEM and DLS data were used to characterize the size and dispersity of the nanoparticles. Preliminary growth analysis data suggests that the iron oxide nanoparticle have an inhibitory effect on E. coli in a concentration dependant manner, whereas the gold nanoparticle directly showed no such activity. However the phase contrast microscopic study clearly demonstrated that the effect of both Fe <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub> and Au nanoparticle extended upto the level of cell division which was evident as the abrupt increase in bacterial cell length. Altogether the study suggests that the metal nanoparticle cell interaction could significantly produce ecotoxicity, challenging its ecofriendly nature.