Introduction:
Herein we report the green synthesis and characterization of silverreduced
graphene oxide nanocomposites (Ag-rGO) using Acacia nilotica gum for the first time.
Experimental:
We demonstrate the Hg2+ ions sensing ability of the Ag-rGO nanocomposites form
aqueous medium. The developed colorimetric sensor method is simple, fast and selective for the
detection of Hg2+ ions in aqueous media in presence of other associated ions. A significant color
change was noticed with naked eye upon Hg2+ addition. The color change was not observed for
cations including Sr2+, Ni2+, Cd2+, Pb2+, Mg2+, Ca2+, Fe2+, Ba2+ and Mn2+indicating that only Hg2+
shows a strong interaction with Ag-rGO nanocomposites. Under the most suitable condition, the
calibration plot (A0-A) against concentration of Hg2+ was linear in the range of 0.1-1.0 ppm with a
correlation coefficient (R2) value 0.9998.
Results & Conclusion
The concentration of Hg2+ was quantitatively determined with the Limit of
Detection (LOD) of 0.85 ppm. Also, this method shows excellent selectivity towards Hg2+ over
nine other cations tested. Moreover, the method offers a new cost effective, rapid and simple approach
for the detection of Hg2+ in water samples.