Application of starch-stabilized silver nanoparticles as a colorimetric sensor for mercury(II) in 0.005 mol/L nitric acid

A sensitive and selective hg2+ optical sensor has been developed based on the redox interaction of hg2+ with starch-coated silver nanoparticles (agnps) in the presence of 0.005 mol l-1 hno3. the relative intensity of the localized surface plasmon absorption band of agnps at 406 nm is linearly dependent on the concentration of hg2+ with positive slope for the concentration range 0-12.5 μg l-1 and negative slope for the concentration range 25-500 μg l-1. experiments performed demonstrated that metal ions (na+,k+,mg2+,ca2+,pb2+,cu2+,zn2+,cd2+,fe3+,co2+,and ni2+) do not interfere under the same conditions,due to the absence of oxidative activity of these ions,which guarantees the high selectivity of the proposed optical sensor towards hg2+. the limits of detection and quantification were found to be 0.9 μg l-1 and 2.7 μg l-1,respectively,and relative standard deviations varied in the range 9-12% for hg content from 0.9 to 12.5 μg l-1 and 5-9% for hg levels from 25 to 500 μg l-1. the method was validated by analysis of crm estuarine water bcr505. a possible mechanism of interaction between agnps and hg2+ for both concentration ranges was proposed on the basis of uv-vis,tem,and saed analyses. © 2017 penka vasileva et al.