Selective detection of arsenic (III) based on colorimetric approach in aqueous medium using functionalized gold nanoparticles unit

We report a simple colorimetric approach for the detection of arsenic (III) through gold nanoparticles functionalized by polyethylene glycol. Following Turkevich procedure nanoparticles were prepared. Owing to addition of arsenic (III), lead (II), copper (II), nickel (II), iron (III), zinc (II), cobalt (II), magnesium (II) and cadmium(II) to the as synthesized gold nanoparticles we observe rapid color change from red to blue with respect to arsenic (III) containing vials. This implicates the selectivity of polyethylene glycol functionalized gold nanoparticles towards arsenic (III). Sensitivity was analyzed from absorbance spectra obtained from UV-vis spectrometer and limit of detection was found to 5 ppb from the linear response curve which is below theWHOguided value 10 ppb.