Uncertainty Measurements in Chemically Synthesized Stable Uniform Sized Gold Nanoparticles for TEM/HRTEM Calibration

The accuracy of an electron microscope depends on the magnification and resolution of the microscope. Hence in order to achieve high accuracy measurement results from the electron microscopic examination, a standard specimen is required to calibrate the transmission electron microscope (TEM). In the present work, gold nanoparticles of uniform size with narrow particle size distribution were synthesized with an aim to use them as reference material (RM) for TEM/high resolution TEM calibration and then release them in market as Bhartiya Nideshak Dravya (BND). As synthesized gold nanoparticles at 20 ± 2 C temperature and 45± 5% relative humidityand the standard sample were characterized by using HRTEM, model: FEI-Tecnai F30 G2 STWIN at suitable magnification and areas. Both images exhibit spherical shaped nanoparticles with size varying in the range from (15.35-20.15 nm) and (5.10 -7.70 nm) respectively. Stability in particles size of the chemically synthesized gold nanoparticles was studied for a period of one year time span using UV-Visible spectrometer. TEM/HRTEM measurements were carried out in automated mode under similar experimental and environmental conditions at different magnifications to get accurate particle size. Overall uncertainty is estimated in small and big size particles as per standard GUM document guidelines.