high-resolution transmission electron microscopy (hrtem) is used to obtain the hrtem images (fei tecnai g2 f20 s-twin working at 200 kv) and double beam uv-visible spectrophotometer is used for the extinction, or removal, of the nps gold spectra. a combination of scanning electron microscope and an energy dispersive x-ray detector (edx) for obtaining edx spectra while sub micrometer particle size analyzer and delsa nano zeta potential measure the potential of gold nps. inductively coupled plasma-mass spectrometry (icp-ms) measures the quantification of mercury species in gold nps while the linear range of hg2+ should be between 2.5 and 50 nm. the powder x-ray diffraction is measured using a diffractometer with cu kα radiation. a superconducting quantum interference device measures the magnetometry while the fourier-transformed infrared spectroscopy spectrum is measured by a nicolet 6700 ft-ir spectrometer.