Sharif Digital Repository

We report herein the development of a highly sensitive colorimetric method for detection of D- Penicillamine using citrate capped gold nano particles (Au-NPs) .This assay relies upon the distance-dependent of gold nanoparticles surface plasmonic resonance band of gold nanoparticles. By replacing the thiol-containg chelator drug, D-Penicillamine, with citrate on the gold nano particles surface, a new peak appearing at a longer wavelength intensifies and shifts further to the red from the original peak position which depends on ionic strength, D- Penicillamine and gold nanoparticles. The ratio intensities of absorbance at longer wavelength (630 nm) to original wavelength (521 nm) allow the... 

Recently, fluorescence resonance energy transfer (FRET) based assay through employing gold nanoparticles have been developed for sensitive and selective detection of various analytes [1,2]. These are due to the extremely high extinction coefficient of Au NPs, which induces fluorescence quenching of the attached fluorophores as a result FRET ; a process which is inversely proportional to the sixth power of the distance between fluorophore and quencher [3]. Upon the addition of the analytes with much stronger affinity for Au NPs, the fluorophore molecules are detached from the surface of the Au NPs results in an increase of fluorescence intensity, which is in direct relation with...