Optimization of a Colorimetric Sensor for Mercury (II) Ion Detection Using Albumin/Silver Nanoparticles

Abstract

Metal nanoparticles have unique properties and different scientific, industrial, and environmental applications. In this study, an optical sensor has been optimized for mercury (II) ion detection. This sensor is based on the redox interaction of Hg (II) ions with Albumin/Silver Nanoparticles (Alb/AgNPs) in an aqueous solution. The addition of Hg (II) ions caused a visual color change from dark brown to colorless. The color change was proportion to the concentration of mercury ions. Different parameters affecting the Hg (II) and Alb/AgNPs interaction, such as the concentration of Alb/SNPs and the time of reaction, were carefully studied and optimized. Under the optimal experimental conditions, the difference absorbance (ΔA) at 440 nm was linearly proportional to Hg (II) ion concentration in the range from 0.293 µM to 2.340 µM with a limit of detection of 0.141µM. The optimized sensor was used to detect mercury (II) ions in samples of lightening cream products