Unmodified Silver Nanoparticles synthesized by solvent reduction method as tool for detection of Cr (VI) colorimetrically in solution

Abstract

A Colorimetric recognition technique of Cr (VI) in watery environment with the help of combined silver nanoparticles (Ag NPs) is devised. The technique includes reducing of Cr (VI) to Cr (III) by the overabundance of a reducing agent present in the synthesised AgNPs dispersion. This reduction leads to the accumulation of silver NPs by Cr (III), prompting red-move of the resonance peak. The UV– vis retention spectra in the wavelength range of 200-

800 nm is used to affirm the collection of the Ag NPs. Cr (VI) upto a concentration of 0.01 M was detected which was further diluted to detect the lower concentrations using the silver nanoparticles probe. The detection was colorimetric as the solution of silver nanoparticles pale yellow in colour changed its colour to purple when Cr (VI) was added to it. Even the method was found out to be extremely selective. Thus a rapid and a simple partially green technique are developed to detect Cr (VI) which was also selective in nature when  tested  over  other  heavy metal ions.