Synthesis of aza-crown ether-modified silver nanoparticles as colorimetric sensors for Ba2+

In this paper, we have demonstrated a facile strategy of preparing aza-crown ether (ACE)-modified silver nanoparticles (Ag NPs) by an efficient nano-conjugate technology named dithiocarbamate. This is the first report of using ACE to modify Ag NPs. ACE-modified Ag NPs have a good recognition of Ba2+, with the detection limit of 10− 8 mol/l. It is reasonable to believe that Ba2+ induced the self-assembly of Ag NPs by the formation of the sandwich structure with ACE.