Nanoparticle Toxicity in Saccharomyces cerevisiae: A Comparative Study Using Au Colloid, Ag Colloid, and HAuCI4 • 3H2O in Solution,Public Deposited
The effects of 13 nm Au colloid and 10 nm Ag colloid on the growth of the yeast species Saccharomyces cerevisiae were compared to control samples cultured in a growth media of yeast extract, bacto peptone, and dextrose (YPD) to determine the toxicity of nanoparticles. Growth curves were generated for various conditions, using UV-Vis spectroscopy (OD600 nm) as a function of time. The initial growth curves generated using Au colloids showed no significant effect on the extent of growth, and a comparative curve using Au and Ag colloids showed similar growth, though the metal concentration of Au colloid was six orders of magnitude lower than that of the Ag colloid. The molarity of Au particles in 13 nm Au colloid solution was calculated at 9.02x10-7M, and a solution of HAuCl4 • 3H2O was prepared to match and exceed the molarity of the Au colloid solution. Growth cycles with various dilutions of HAuCl4 • 3H2O were monitored from 9.02x10-7M to 1.5x10-3M Au. Increasing Au molarity resulted in decreased growth. Growth was enhanced at low concentrations of Au (up to 3.6x10-4M Au); at high levels of Au (9.1x10-4 to 1.5x10-3M), growth was decreased below the level of the control (in which no Au was added). 1.5x10-3M Au in HAuCl4 • 3H2O solution resulted in no growth over a period of 20 hours.