Abstract:

Nanoparticles are widely used in medical diagnosis and treatment, as carriers of drug preparations, in cosmetics, production packaging and transportation of foods and etc. Special attention is paid to the use of biological structures in the production of nanoparticles. The aim at the presented work was to investigate the influence of temperature on the formation of silver nanoparticles by Candida macedoniensis BSU-MI44. Wet biomass of yeast at AgNO3 solution, was incubated at 25, 30, 35, 40°C. The samples have been analyzed on the UV spectrometer, the scanning electron microscope and the X-ray spectroscope. Spectrophotometric analyses showed 410 nm wavelength (peak), characteristic for silver nanoparticles in samples incubated at 25 and 30°C. By increasing temperature, the formation of silver nanoparticles has weakened and has finally stopped. The optimum temperature was between 25-30°C for the production of silver nanoparticles and the formed nanoparticles were spherical at both temperatures. The sizes of silver nanoparticles formed at 25°C and 30°C were 65.6 and 14.2-22.9 nm. The sizes of the first ones have been 2.8-4.7 times larger than the sizes of the others. Correspondingly X- ray spectroscopic analyses of the obtained samples showed the characteristic absorption peak for silver nanoparticles formed at temperatures 25 and 30°C.

Keywords: