Cooperative Binding of Bifunctionalized and Click-Synthesized Silver Nanoparticles for Colorimetric Co2+ Sensing

Bifunctionalized silver nanoparticles (triazole-carboxyl Ag NPs) were synthesized through a click reaction and have a cooperative effect on recognition of Co2+, resulting in appreciable changes in color and absorption properties over other metal, ions tested, including Fe2+, Mn2+, Hg2+, Ni2+, Cd2+, Cu2+, Zn2+, Pb2+, Li+, Na+, K+, Cs+. The functionalized silver nanoparticles became aggregated in solution in the present of Co2+ through cooperative metal-ligand interaction. The colorimetric sensor allows a rapidly quantitive assay of Co2+ down to the concentration of 7.0 x 10(-6) M. Moreover, the triazole-carboxyl AgNPs can be capable of evaluating the exceeding standard of Co2+ in drinking water.