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

Abstract

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 × 10⁻⁶ M. Moreover, the triazole-carboxyl AgNPs can be capable of evaluating the exceeding standard of Co²⁺ in drinking water.